Short args that take values should be able to have the value immediately after the arg

[Hejsil]

This should work: command -Dvalue. Here, value is the value of the argument D, if D is a short arg and takes a value.

Questions:

• Should this be allowed? command -value, where v is a short arg, and alue is its value?
  • I think this is a question of good argument design. If people wanna design their options in a poor way, we can't/shouldn't really stop them.
• Should this work with chaining? -aDvalue, where a and D are short args. a doesn't take a value, and D does.
  • I don't think I should, but I need to look into how other claps does this.
  • Maybe it should work though, as -aD=value works.
• Should this work: command -Dvalue=2? Here, D is a short arg taking a value, and value=2 is its value.
  • This would allow for user implemented custom runtime arguments, which is currently not supported by the lib itself.