manifest embedding in onefile and uac admin and uiaccess support

The patch does 2 things

1. In onefile mode embeds the manifest into the executable (in onedir mode it is already being placed along the executable)

2. Adds 'uac_admin' and 'uac_uiaccess' keyword arguments to EXE to allow automatic manipulation of this permissions in the manifest (for both onefile and onedir modes)
Could you please add command-line options --uac-admin and --uac_uiaccess to the config.py to allow usage of these options directly from command prompt without the need to create and edit .spec file first.
Help text for these options would be similar as to this doc string. And please also mention these new options in the manual.

Thanks.