Revert "Revert "Bug 717062 - Root preferences branch for simple-prefs needs to be configurable r=@erikvold""

This reverts commit 3784678ed07b074295bacd7d67ca259b043c0b8c.
Bug 717062 exposing require("sdk/self").preferencesBranch
Merge branch 'master' of github.com:mozilla/addon-sdk into 717062v2
Bug 717062 Adding regression test
Bug 956626 - Convert periods to text in widget IDs. r=zer0
Bug 958908 - Remove usage of deprecated/observer-service
Merge branch 'master' of github.com:mozilla/addon-sdk into 958908

Conflicts:
	lib/sdk/content/worker.js
	lib/sdk/deprecated/symbiont.js
Merge pull request #1343 from erikvold/958908

Bug 958908 - Remove usage of deprecated/observer-service r=@jsantell
Bug 793266: Remove app-strings and api-utils#publicConstructor
Merge pull request #1348 from jsantell/793266-remove-app-strings-andpublic-constructor

Fix Bug 793266: Remove app-strings and api-utils#publicConstructor, r=@erikvold
Merge pull request #1333 from jryans/button-view-id

fix Bug 956626 - Convert periods to text in widget IDs r=@ZER0
bug 958609 - add note about Python 2.7.6 to README

and update documentation links to MDN
Bug 933971 Loader should throw on subsequent requires if invalid
Merge pull request #1351 from jsantell/933971-loader-test-throw-on-invalid

Fix Bug 933971 Loader should throw on subsequent requires if invalid, r=@ZER0
Hot Fix for breakage from Bug 933971
Bug 783047 - Update SafeBrowsing URLs to use HTTPS. r=mmc,dcamp sr=gavin
bug 958609 - don't imply future fixes
Merge pull request #1352 from zombie/958609-python-276

bug 958609 - add note about Python 2.7.6 to README
Merge branch 'master' of github.com:mozilla/addon-sdk into 717062v2

Conflicts:
	lib/sdk/simple-prefs.js
Merge pull request #1211 from erikvold/717062v2

Bug 717062 Redux - Root preferences branch for simple-prefs is now configurable r=@Mossop