Improved grid values and grid bounds representation

Replaces the (pointer to double) attribute fields with (std::vector<double>) values [same for fieldWithLevel]
Ponters are still available as return values of 'getValuesAsPointer' and 'getValuesWithLevelAsPointer'

Use rpath to non installed libcdi for testing
Ruby binding still throws errors on calling 'getField'

Added libtool built libcdi.so to python interface creation
python interface itself is not built with libtool, yet

Configure gets triggerd by CDO's configure call for non installing libcdi.la
through a shell variable, so '--enable-cdi-lib' is removed (refs #492)

This is the default build for CDO. 'make distcheck' still checks 
building + installing the library + testing app (refs #492)

refs #480