Add GoTo features for python

This adds a Go To Definition and Go To Declaration features for
python.
remove not needed type casting
Add GoToDefinitionElseDeclaration for python
style fixes
Merge pull request #292 from JazzCore/goto_python

Add Go To features for python
Code style fixes
Updating docs to mention Python GoTo* support
Making -fPIC the default

Fixes #211
Updating vimdoc from readme