Updated MakefileWorker.mk to also handle .cc files.

Minor updates to let the MakefileWorker.mk handle .cc files. Also removed some extra tabs.

I noticed this was discussed earlier in May:
https://groups.google.com/forum/#!searchin/cpputest/makefileworker/cpputest/bh-Lqqxcv4E/cJVtzm6r4gcJ