Moved Visual Studio specific compiler flags for RelWithDebInfo config
to the right place.

This fixes #122.
Expanded the search for boost libs.

In case there is not a static linked boost lib version now it will be searched for dynamic linked boost lib, too.
Search for static libs first.
Merge pull request #123 from TomFischer/CMakeBoostChanges

Expanded the search for boost libs.
Restricted linking to the needed boost lib only.
Merge pull request #125 from TomFischer/CMakeBoostChangesPartII

Restricted linking to the needed boost lib only.

This should also fix #124. Please repoen the issue if not.