Properties support for javascript bindings and typescript generation

[edkilday]

Add property support to ACT for the javascript bindings.

ACT XML method tags have new attrributes.

<class name="Point
  <method name="GetX" propertyget="X" ...>
  <method name="SetX" propertyset="X" ...>

Javascript bindings created

Point.X = 0.0
var x = Point.X

The ACT generator can also output a typescript representation. To generate the bindings add a new implementation tag to the XML interface definition.

<implementations>
	<implementation language="TS" indentation="tabs"/>
</implementations>

Notes for the reviewer.
There are a lot of formatting changes in Source/buildimplementationjs.go so I've separated them in this commit for easier viewing.