updates in cmake build

Hello,
I've updated cmake build.

Summary:
- added source_group(...) to handle msvc ide subfolders
- fixed BULD_SHARED_LIBS=ON/OFF flag to correctly build shared/static libraries on Win/Linux (MacOSX is not checked)
- minor updates in macroses
- added .travis.yml for travis-ci.org check

Could you please review and integrate?
Thank you.