Refactor blocks, programs and inverses
added test multiple subexpressions in a hash with context
Do not flush subexpressions

They are no longer duplicated with the new helper calling pattern and this also introduced stack corruption issues due to improper value lookups.

Fixes #767
Fixes #768
Merge branch 'evensoul-master'
Remove unnecessary stack variable from blockHelper
Optimize replaceStack for inline methods

Only use case was with inline input so most of this code was unnecessary.
Merge branch 'refactor-parser' of github.com:mmun/handlebars.js into mmun-refactor-parser

Conflicts:
	lib/handlebars/compiler/ast.js
	spec/ast.js
	src/handlebars.yy
Merge branch 'mmun-refactor-parser'
Add original value tracking to ContentNode
Replace string value rather than add omit flag
Move strip processing into AST helper logic

We already have to track these behaviors for the standalone parsing and rather than having two whitespace pruning implementations this moves all of the behavior into one place.

Fixes #852
Cleanup from code coverage report
Restore helperMissing for ambiguous statements

Fixes #318 (regression)
Partial fix for #783
Additional test coverage cleanup

Also fixes the template._child implementation which broke with the depthed work.