Implement addon/window API.
Simplify hidden-frame implementation by using
addon/window instead of platform specific hidden one.
Write tests for system runtime.
Write tests for system/events.
Handle case where access of `runtime.XPCOMABI` throws.
adding a private-browsing key to the package.json
Merge branch 'master' of https://github.com/mozilla/addon-sdk into 820582
exposing the private-browsing flag to runtime
Merge branch 'master' of git://github.com/mozilla/addon-sdk into 820582
Merge branch '828746' into 820582
bug 820582: fix for tests that used loader w/out metadata
Bug 837537: mentioning how to access simple-prefs via the preferences/service module
Bug 841536 - Improve console message on some platform exception with undefined message/name
Bug 784224: Page-mod tests now work on Fennec
Merge branch 'master' of https://github.com/mozilla/addon-sdk into 820582

Conflicts:
	test/test-private-browsing.js
bug 820582: review updates, self module now exports isPrivateBrowsingSupported, and there is a test that this is true when it should be
Bug 820582: address review comment on diff in lib/sdk/loader/cuddlefish.js
Bug 820582 adding baisc docs, more to come
Bug 837537: address review comments
Bug 840014: tabs.open() and windows.open() now take a isPrivate option