New argument parsing for bsputil broken

[dsvensson]

The new argument parsing to bsputil expects operations such as --extract-textures to take an argument.

That is, this fails:

bsputil --extract-textures foo.bsp

...while...

bsputil --extract-textures dummy foo.bsp

...works.

Given the new argument parsing I also suspect that #224 is invalid.

[ericwa]

Thanks for catching.

I fixed --extract-textures and --extract-entities. I'll need to test the other bsputil commands and ideally add automated tests for all commands.