More MXML improvements

- Added event completion support. Decided to make matches lookup more
relaxed than the one in other IDEs.
- Added function type completion support.
- Added Inspectable metadata support. This required some global
ActionScript metadata parsing improvements.
Fixed a NRE  in some functions without arguments
Metadata intrinsic generation
Changed how metadata intrinsic is generated.
Merge pull request #279 from Neverbirth/mxml/intellisenseimprovement

Mxml/intellisenseimprovement