Added a description to the global version switch.
Changed output if a global version switch is used. Show only the version number.
Add failing test for command with no command options
Fix failing test for command with no command option
Fix remaining tests
Add a few more unit tests for the command/global options
Merge remote-tracking branch 'calestar/synopsis_fix' into gli-2
tweak fix for #147 and #119 to account for recent changes

Closes #147
Closes #119
Merge remote-tracking branch 'brainknight10/138-version-switch' into gli-2

Conflicts:
	lib/gli/app_support.rb
--version now just shows version

Closes #143 (thanks @brianknight10 for the test coverage!)
Extract app name to method instead of using $0
exit nonzero from falsey precondition

Closes #146

Does two things:

* if pre is false, we exit nonzero
* given how we exit, if GLI_DEBUG is set, you get a stack trace
Firm up aruba dep to avoid spurious bug