Fix problem parsing stuff like options: --compile-java-args='-target 7 -source 7' in pants.rc files

Testing Done:
Ran new tests

Reviewed at https://rbcommons.com/s/twitter/r/1192/
Sync of https://github.com/pantsbuild/pants/commit/77ccbb69f9df8882105a03d0e5bb13933e375a5b