Assign local variable - quick assist

pdt-eg/Core-Plugin#7

Just like in JDT/JSDT. Allow create variable directly from function/method call, class instance creation

Without pdt with this patch: https://bugs.eclipse.org/bugs/attachment.cgi?id=236083 works only with normal functions.

TODO:
1. Collision detection
2. Extend PDT to allow inject command shorcut
3. Select image (any ideas?)