Bug 875289 - Renaming Future to Promise, r=mounir

--HG--
rename : dom/future/Makefile.in => dom/promise/Makefile.in
rename : dom/future/Future.cpp => dom/promise/Promise.cpp
rename : dom/future/Future.h => dom/promise/Promise.h
rename : dom/future/FutureCallback.cpp => dom/promise/PromiseCallback.cpp
rename : dom/future/FutureCallback.h => dom/promise/PromiseCallback.h
rename : dom/future/FutureResolver.cpp => dom/promise/PromiseResolver.cpp
rename : dom/future/FutureResolver.h => dom/promise/PromiseResolver.h
rename : dom/future/moz.build => dom/promise/moz.build
rename : dom/future/tests/Makefile.in => dom/promise/tests/Makefile.in
rename : dom/future/tests/moz.build => dom/promise/tests/moz.build
rename : dom/future/tests/test_future.html => dom/promise/tests/test_promise.html
rename : dom/future/tests/test_resolve.html => dom/promise/tests/test_resolve.html
rename : dom/webidl/Future.webidl => dom/webidl/Promise.webidl
Bug 875289 - Remove .done() and allow undefined to be passed to .then() and .catch(), r=mounir