browser dependencies via bower (with a few exceptions)

exceptions:

requirejs: author refuses adding minified version, keeping it in amber
jquery-ui: keeping shorter customized version
Merge branch 'master' into bowerize
adds required css file for codemirror
Fixes issue #143
Fixes issue #681
Fixes issue #690.
Adds accessors to the constructor of classes.
Fixes issue #674
Fixes issue #421
Makes code completion much faster.
Adds "Ubuntu Mono" to the code fonts of Helios
More font changes to Helios code widget
cleaner fix for issue #143. See comments on https://github.com/amber-smalltalk/amber/commit/97cc25cba063722aeb75cab7b293fd74ffe1feb3
Change string's identity hash to receiver + 's'
tabifies support/devel.js
load codemirror's css before the addon.
README.md: Building amber includes bower dependencies
- Removes MethodContext >> pc
- Adds MethodContext >> sendIndexes
Adds IRInstruction >> scope
Adds JSStream >> nextPutSendIndexFor:
typo