Bug 946025 : [B2G][Settings][Internet Sharing] Enabling Wi-fi hotspot without a SIM card inserted does not
bug 975850

* Stack Manager should start up with _current set to -1 since we launch the homescreen by default.
* Cards View should show most recently used application (last on stack) when the homescreen is being shown.
* Added tests for showing cards view from homescreen in default running state (eg. no recent apps)
* Added tests for stack manager to ensure that position is always -1 initially.
* Seperated the tests for cards view active, one set for in the rocketbar, one set for outside of the rocketbar.
** The original test covered the default running state case, it was updated for the task manager being shown in
   rocketbar but we did _not_ backout that change when disabling the rocketbar in 1.4.
* call blur on AppWindow instead of on frame.

r=alive
Bug 968679 - [settings] add marionette test for Sound panel
Bug 962352 - restore the caller only when activity callee is active
Merge pull request #15899 from leob2g/Bug_946025_Enabling_wifi_hotspot_without_a_SIM_card_inserted_does_not_prompt_user

Bug 946025 - [B2G][Settings][Internet Sharing] Enabling Wi-fi hotspot without a SIM card inserted does not prompt user, r=alive
Merge pull request #16580 from nullaus/bug975850-cards-view-stack-manager

bug 975850
Revert "Bug 971648 - Add warning message if there is no"

This reverts commit b8e0bb360d369e7f1bbcf13a6f8d34abd74a0c63.
Merge pull request #16112 from gasolin/issue-968679

Bug 968679 - [settings] add marionette test for Sound panel, r=arthur
Merge pull request #16598 from alivedise/bugzilla/962352/do-not-restore-caller-on-home-button

Bug 962352 - restore the caller only when activity callee is active, r=timdream
Bug 968294 - Refresh authentication UI. r=alive