Simplify BlockNode by removing intermediate MustacheNode
Remove RawBlockNode in favor of prepareRawBlock helper
Merge branch 'remove-block-mustache' of github.com:mmun/handlebars.js into mmun-remove-block-mustache

Conflicts:
	lib/handlebars/compiler/helpers.js
	spec/parser.js
Merge branch 'mmun-remove-block-mustache'