Enhance perform-cppcheck script
Enhance perform-cppcheck script

to allow running in cygwin environments.

RealityFactory/CEGUI,arkana-fts/cegui,RealityFactory/CEGUI,arkana-fts/cegui,arkana-fts/cegui,arkana-fts/cegui,cbeck88/cegui-mirror,cbeck88/cegui-mirror,RealityFactory/CEGUI,arkana-fts/cegui,RealityFactory/CEGUI,cbeck88/cegui-mirror,cbeck88/cegui-mirror,RealityFactory/CEGUI,cbeck88/cegui-mirror