Cleaned -Wunused-variable and -Wunused-local-typedefs warnings for a cleaner build experience

These rogue variables have been causing a lot of mess on build output.
Cleaned them to make the build smoother (and prettier!)
Everything else is unaffected.
Merge branch 'master' of https://github.com/opencog/opencog
Merge pull request #219 from 5aurabhpathak/master

Cleaned -Wunused-variable and -Wunused-local-typedefs warnings for a cleaner build experience