* Remove a race in open_log_file()
* Make open_log_file return a path as well as a file-object so that
Rainbow-launched activities can log to the same path that sugar-launched
ones do.
* Change the call to Rainbow so that it writes to the log-file provided by
open_log_file()
* Define SUGAR_BUNDLE_ID env variable and change the location of the check
for /etc/olpc-security so that Rainbow doesn't have to search for or parse
the activity bundle.
* Remove import statements marked as unnecessary by pylint.
* Fix up some whitespace issues.
