Print common options to 'gmx -h'
The help shown for the wrapper binary now includes the command line
options it accepts. Remaining issues that will be fixed separately:
- Unlike other help output, this output is actually influenced by what
the user specifies on the command line.
- The information is not so easy to find, because of the long list of
subcommands that comes after it.
- The information should go to some man page as well.
Related to #685.
Change-Id: Iac72dd21d4a733016b331549e139d4184bd3e283