<rdar://problem/13312903>

Exports write() and flush() from SBCommandReturnObject to enable file-like output from Python commands.
e.g.:
def ls(debugger, command, result, internal_dict):
    print >>result,”just “some output”

will produce
(lldb) ls
just “some output
(lldb)
Added better measurements to test:
- memory delta and time for: target create
- memory delta and time for: setting breakpoint at main by name
- time to launch and hit bp at main
- overall memory of target create + bp main + run to main
- ovarall time of target create + bp main + run to main