Bug 908162 - Removes Button module's dependency from Sidebar module

 - removed `sdk/ui/button` dependencies and `sdk/ui/state` dependencies
 - removed `icon` property
 - removed `CustomizableUI` dependencies
 - thrown a new Error if the ID is already used in create method of `ui/sidebar/view`
 - updated tests
 - replaced metadata: sidebar is not compatible only with australis now
 - replaced deprecated for each loop with `for..of`
 - disabled `testSidebarIsOpenInNewPrivateWindow` in `private-browsing-supported`
Merge pull request #1216 from ZER0/sidebar/908162

fix Bug 908162 - Removes Button module's dependency from Sidebar module r=@erikvold
Bug 910190 - Fix jetpack test failures in test-ui-button.js, r?zer0
Add debugging information when panel.destroy throws.
Merge pull request #1224 from Mossop/bug910230

Add debugging information when panel.destroy throws to help figure out bug 910230 r=kwierso
Merge pull request #1223 from gijsk/bug910190

fix Bug 910190 - Fix jetpack test failures in test-ui-button.js r=@ZER0
Workaround issues with syntax errors not
containing filename of the file with an error.
Bug 865391 - Intermittent Jetpack TEST-UNEXPECTED-FAIL | unknown | Test output exceeded timeout (300s).

- Log infos
Merge pull request #1217 from ZER0/unknown-test/865391

Bug 865391 - Intermittent Jetpack TEST-UNEXPECTED-FAIL | unknown | Test output exceeded timeout (300s). a=@gozala
Bug 782824 tests for modules that do not exist
Merge pull request #1213 from jsantell/782824-tests-for-dne-modules

Fix Bug 782824 tests for modules that do not exist, r=@erikvold
Fix circular require in page-mod/match-pattern.js

This should refer to util/match-pattern.js instead, so that
existing code using page-mod/match-pattern doesn't break.
Merge pull request #1231 from legoscia/patch-1

Fix Bug 911498 Fix circular require in page-mod/match-pattern.js, r=@jsantell
Merge pull request #1227 from Gozala/bug/workaround@910653

Bug 910653 - Workaround issues with syntax errors r=@zer0