Merge pull request #7 from dbeck/master

restructure Makefiles and fix Linux and Mac builds
Adding expect to test.
Added a very basic/trivial test
Adding some filters to generic fdw.
Expression class now correctly handles composite expressions.
Some expects got uncommented.
Merge pull request #8 from szilardhuber/master

Finished testing of Expression class
Merge pull request #9 from szilardhuber/feature-148

Feature 148 - Added filters to generic FDW