Include name option for all helper calls

All helper calls will have access to `options.name` which is the first id value of the mustache operation.

As part of this the helperMissing call has been simplified to remove the indexed name in order to optimize the call. This is a breaking change.

Fixes #634
Cleanup now unused code in jscompiler
README: Use with helper instead of relying on blockHelperMissing
Merge pull request #706 from scottgonzalez/readme-with

README: Use with helper instead of relying on blockHelperMissing
Attempt manual install of git in travis
Merge pull request #707 from wycats/git-fix

Attempt manual install of git in travis
Expose the initial context via @root
Merge pull request #392 from wycats/root-data

Access to root context in partials and helpers
Merge pull request #634 from wycats/name-option

It would be great to have the helper name passed to `blockHelperMissing`
Improve usefulness of extend util, properly use namespace property, update setup options to use a hash helper.
Merge pull request #704 from blakeembrey/clean-compiler

JavaScript Compiler Cleanup
Remove apt git install
Use git describe to lookup tag
Merge pull request #711 from wycats/git-tag

Attempt to resolve git tag using describe
Add partial hash parser support
Implement partial hash evaluation
Test more concrete behavior in partial hash test
Merge pull request #182 from wycats/partial-hash

Context different for partial
Allow implicit context iteration with each

Fixes #671
Always process explicitly passed files in CLI

Fixes #689