Add a usage example of SBEvent APIs.
o SBEvent.h and SBListener.h:
Add method docstrings for SBEvent.h and SBListener.h, and example usage of SBEvent into
the class docstring of SBEvent.
o lldb.swig:
Add typemap for SBEvent::SBEvent (uint32_t event, const char *cstr, uint32_t cstr_len)
so that we can use, in Python, obj2 = lldb.SBEvent(0, "abc") to create an SBEvent.
llvm-svn: 134766