daniel-export: don't exit from option parser
daniel-export: don't exit from option parser

This breaks the ability to test option parsing in a spec down the line.
Avoid calling exit; instead, set a flag on --help, and return from the
main function in such a case.

Signed-off-by: brian m. carlson <738bdd359be778fee9f0fc4e2934ad72f436ceda@crustytoothpaste.net>

bk2204/daniel-ruby,bk2204/daniel-ruby