proctor-builder: Fix option lookups by using short name

Hi folks,

I've been having trouble using proctor-builder to compile my set of test definitions into a single test matrix file. Any attempted to execute results in a NPE, as all of the options were being read as null

After debugging, I found that the code uses getOptionValue() and hasOptionValue() with the long option names, while the Apache cli library expects the short/character names:
http://commons.apache.org/proper/commons-cli/javadocs/api-1.1/index.html

With this small patch, I was able to generate my file successfully.

Thanks,
-Eloy Perez
eloyperez@homeaway.com