Modify name interpolation behaviour to comply with the spec for method calls. All metods in a name path should be called in the context of their containing object. In current mustache.js only the last name in a path is called and it is called in the context of the name lookup rather than of its object. This patch breaks the current behaviour, so I provided an extra context parameter to make it easier to update programs using the current function context behaviour. A breaking test is fixed and there are new tests for method calls etc.
Update README.md

Updated documentation for the new method interpolation behavior.
Merged in topic/method-interpolation-compliance, all promise testing feels clumsy, but at least the tests succeeds.