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
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`