Make Most Unit Tests Independent of LibECL

This commit switches a set of OPM-Common's unit tests away from
using direct calls to libecl functions and into using base types
from OPM-Common itself (along with Boost.Filesystem).

In particular summary related queries are replaced by calls to ESmry
member functions (wrapped in libecl-like interfaces to minimise code
changes).  We disable checks on unit strings since ESmry currently
does not have a way of associating those with individual variables.

tests/parser/ACTIONX.cpp

@@ -26,8 +26,6 @@
 #include <boost/test/unit_test.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
 
-#include <ert/util/util.h>
-
 #include <opm/parser/eclipse/EclipseState/Grid/EclipseGrid.hpp>
 #include <opm/parser/eclipse/EclipseState/Schedule/SummaryState.hpp>
 #include <opm/parser/eclipse/EclipseState/Schedule/Schedule.hpp>