Fix "\\{{" immediately following "\{{"

Escaped-escape mustaches ("\\{{") immediately following escaped
mustaches ("\{{") were being handled incorrectly.

Fix the lookahead to make sure yytext still contains the appropriate
slashes when we pop out of <emu> so they can be handled consistently
by the initial state.
Handle empty responses from partials

Fixes #675
Provide default sort for builds link
Add test case to cover #676

Fixes #676
Add notes on bower install

Fixes #655
Add docs on testing ember integration
Merge pull request #641 from wycats/ember-testing

Document ember testing process
Fix handling of boolean escape in MustacheNode

Fixes issue with Ember compatibility due to direct instantiation of MustacheNode.
Add AST test coverage for more complex paths
Merge branch 'fix-escapes' of github.com:dmarcotte/handlebars.js into dmarcotte-fix-escapes

Conflicts:
	spec/tokenizer.js
Add browserify runtime export

Fixes #668
Use env.VM to lookup runtime methods

Allows for overrides by 3rd parties

Fixes #679
Add JavascriptCompiler public API tests
Expose compilerInfo and checkRevision as APIs

Fixes #656
Do not minimize multiple times
Remove unused var
Cleanup jshint globals a bit
Update sauce tests for supported versions
Update release documentation
Update release notes