Readme: Use an SVG badge.

Using the up-to-date badge design.
Minor test cleanup
Fix type in README

Fixes #843
Remove unused JSCompiler.register method
Allow compat flag in test specs
Update to latest saucelabs lib
Parse context sections by line
Track root status in ProgramNode constructor
Flag standalone nodes in the AST
Drop omitted content tags from generated output
Render indent for standalone partials
Add additional tests for standalone partials
Merge pull request #846 from espadrine/patch-1

Readme: Use an SVG badge.
Merge pull request #787 from wycats/standalone-mustaches

Remove whitespace surrounding standalone statements
Create contextName helper for context lookup
Use depths array rather than passing array args

Approximately doubles the throughput performance of depthed templates and clears the way for doing recursive path lookups in pathed mode.
Avoid depth construction overhead for non-depthed
Implement recursive field lookup in compat mode

Provides the mustache behavior of recursive lookup without the use of depthed paths.

Note that this does incur a fairly dramatic performance penalty for depthed queries.
Merge pull request #819 from wycats/compat-mode

Implement recursive field lookup
Inherit compat flag for partials