Bug 853341 - Add Timothy Guan-tin Chien and Jordan Santell as contributors in credits.md

 - Added contributors
 - Removed unnecessary comments for ending blocks of name, now that they are grouped by letters
Remove workaround that was hard to uplift.
Bug 847840 - TEST-UNEXPECTED-FAIL | tests/test-selection.test Selection Listener on frame | Test output exceeded timeout (60s).

Tried to wait the `document-shown` notification before resolve the window, and also move the shutdown functions (`close`, `loader.unload`, `done`) for the test that sometimes is failing.
Documentation for URL.isValidURI
Merge pull request #925 from jsantell/document-isvaliduri-857909

fix Bug 857909 Documentation for URL.isValidURI, r=@wbamberg
Documentation for util/array and util/object
Merge pull request #926 from jsantell/document-utils-857354

fix Bug 857354, Documentation for util/array and util/object, r=@wbamberg
Allow URL instances in Request
Merge pull request #927 from jsantell/request-using-url-857902

Fix bug 857902 - Allow URL instances in Request r=@erikvold
Merge pull request #908 from ZER0/selection-timeout/847840

Bug 847840 - TEST-UNEXPECTED-FAIL | tests/test-selection.test Selection Listener on frame r=@Mossop
Merge pull request #889 from Gozala/bug/remove-method-workaround@839746

Bug 839746 - Remove workaround that was hard to uplift. r=@zer0
Remove added frame on unload.
Remove traits from the panel implementation.
Merge pull request #928 from Gozala/bug/private-panels@816257

Bug 816257 - Detraitify panel implementation. r=@ochameau
Merge pull request #929 from Gozala/hotfix/unload-frame

Bug 859860 - Remove added frame on unload. r=@ochameau
Bug 837494 - re-implement `contentStyle*` using the new nsIDOMWindowUtils methods

- added `mod` module, with `attach`, `detach`, `attachTo`, `detachFrom` and `getWindowTarget`
- added `loadSheet` and `removeSheet` to `stylesheet/utils`
- added `Style` object in `stylesheet/style`
- replace usage of stylesheet services with `attach`/`detach` a `Style` object
- added `weak-set` module
Merge pull request #839 from ZER0/contentStyle/837494

fix Bug 837494 - re-implement `contentStyle*` using the new nsIDOMWindowUtils methods r=@gozala
Merge pull request #883 from ZER0/credits/853341

Bug 853341 - Add Timothy Guan-tin Chien and Jordan Santell as contributors in credits.md
Bug 858935 - Intermittent test-tabs.testOnPageShowEvent | Page was not cached after 5s
Bug 859009: URL is valid type for panel.contentURL
(cherry picked from commit cd5bd30c99ac4050e735344d2b3cfb3fae82af1a)

Conflicts:
	lib/sdk/content/loader.js