Add some more docstrings (includng example usages) to SBTarget.h.

Add logic to modify-python-lldb to correct swig's transformation of 'char **argv' and 'char **envp'
to 'char argv' and 'char envp' by morphing them into the 'list argv' and 'list envp' (as a list of
Python strings).

llvm-svn: 135114