I have noticed that the rendering of <ui:menuList> has changed from Summer '15 to Winter '16, even though I cannot find any documentation of this change.

The behavior is this: We have a <ui:menuList> tag with a custom class name ("customClassName") like this:

<ui:menuList class="customClassName" ..... >

In Summer '15 this renders as:

<div class="customClassName popupTargetContainer uiPopupTarget uiMenuList visible" .... >
    <div role="menu" .... >
    ....

In Winter '16 this renders this way:

<div class="customClassName popupTargetContainer uiPopupTarget uiMenuList" .... >
    <div class="customClassName" role="menu" .... >
    ....

Notice that the second <div> now has the same class as the first <div> ("customClassName"). We use this class to style the first <div>, but now that the second <div> also get the same class, that second <div> is also styled like the first one. This is causing our menuList to display incorrectly.
It seems strange that this is on purpose. My opinion is that it's rarely you want a child div have the same class as the parent. And in this case, when I code the .cmp, the only thing I can add a class name to is the <ui:menuList> tag. When it then renders both divs with that class, it does not seem right.

I should note that I have been able to find a workaround for now (it's not pretty at all; I use jQuery to remove the class from the second div...).

Here is the some sample code to reproduce this:
** CMP code:

<aura:component >
    <ui:menu>
        <ui:menuTriggerLink aura:id="menulist_trigger_id" label="Menu List" class="customClassName"/>
        <ui:menuList class="customClassName" aura:id="menulist_id" >
            <aura:iteration items="Item 1, Item 2, Item 3" var="item">
                <div>{!item}</div>
            </aura:iteration>
        </ui:menuList>
    </ui:menu>
</aura:component>

** Expected outcome (as in Summer '15) (I have removed all auto generated aura attributes for readability):

<div class="customClassName popupTargetContainer uiPopupTarget uiMenuList" style="top: auto;">
    <div role="menu">
        <ul role="presentation">
            <li role="presentation" class="uiMenuItem">
                <a role="menuitem" href="javascript:void(0);" class="selectable">Item 1</a>
            </li>
            <li role="presentation" class="uiMenuItem">
                <a role="menuitem" href="javascript:void(0);" class="selectable">Item 2</a>
            </li>
            <li role="presentation"  class="uiMenuItem">
                <a role="menuitem" href="javascript:void(0);" class="selectable">Item 3</a>
            </li>
        </ul>
    </div>
</div>

** Rendered in Winter '16 (I have removed all auto generated aura attributes for readability):

<div class="customClassName popupTargetContainer uiPopupTarget uiMenuList" style="top: auto;">
    <div class="customClassName" role="menu">
        <ul role="presentation">
            <li role="presentation" class="uiMenuItem">
                <a role="menuitem" href="javascript:void(0);" class="selectable">Item 1</a>
            </li>
            <li role="presentation" class="uiMenuItem">
                <a role="menuitem" href="javascript:void(0);" class="selectable">Item 2</a>
            </li>
            <li role="presentation"  class="uiMenuItem">
                <a role="menuitem" href="javascript:void(0);" class="selectable">Item 3</a>
            </li>
        </ul>
    </div>
</div>

Any one else seeing this?

Are custom labels supported in a Lightning App/Component? We need some way to translate labels and text in our Lightning App, but as far as I can see, {!$Label.xxxx} is not supported. I get this error message when trying to save the component: "ERROR: Labels should have a section and a name: xxxx: Source".

If it is not supported, does anyone have another suggestion on how to solve this?
 

Are custom labels supported in a Lightning App/Component? We need some way to translate labels and text in our Lightning App, but as far as I can see, {!$Label.xxxx} is not supported. I get this error message when trying to save the component: "ERROR: Labels should have a section and a name: xxxx: Source".

If it is not supported, does anyone have another suggestion on how to solve this?
 

I cannot change the Authentication Service under My Domain Authentication Configuration after I did a refresh of my sandbox. After I did the sandbox refresh I configured the SSO settings and uploaded the IDP certificate provided from my IDP. I enabled SAML and try to get the authenticaton service to point to my SSO under the My DOmain - Authentication Configuration.
I am using SSO and am trying to have it so that if they go to my SFDC domain.

Expected Behavior:
When I go to https://my-domain.my.salesforce.com to be redirected to www.domain.com/sso to use my SSO credentials.

Actual Behavior:
When I go to https://my-domain.my.salesforce.com it stays on that page and I cannot use my SSO credentions. When I attempt to change the Authentication Service under Domain Management -> My Domain -> Authentication Configuration it always reverts back to Login Page

If I try to disable the SAML in the SInge Sign On Settings page is gives me the error message: Error: Your organization or community is currently using SAML as an authentication method, so you can’t disable it.
So my problem is that I can not disable SAML or I can active the use of SSO authenication. 

I am confident the SSO settings are correct as they are the same as before the Sandbox refreshed where it worked just fine.
The Authentication Service under Domain Management -> My Domain -> Authentication Configuration always reverts back to Login Page seems to be the key issue her.

Please help