Probe explicitly for OpenMP

opm-core contains code which has #pragma omp. Earlier, OpenMP was
detected as part of the probe for ERT. However, that probe got
smarter, and as a result doesn't probe for more than it needs. Thus,
we need to check for OpenMP explicitly in opm-core. (It is disabled
by default)
Merge pull request #181 from rolk/182_openmp

Probe explicitly for OpenMP
Make destructor of CompressibleTpfa virtual.
Fix error in doc.
Removed some unused mex-interfaces.
Remove more unused mex-interfaces.
Merge pull request #185 from atgeirr/minor-fixes

Minor fixes
Simplify setting of flag that indicates shared object

Instead of having the name of the module set for each flag, use the
available standard option. Mixing shared objects and static libraries
in the same build is not a very realistic scenario anyway.

This enables us to call configure without actually having a particular
module; the script may then be used on a group level.
Moved opm/core/eclipse/* to opm/core/io/eclipse/*.
Moved opm/core/vag_format/ -> opm/core/io/vag/
Moved writeECLData and writeVtkData to opm/core/io subdirs.
Merge pull request #186 from rolk/186_configure

Simplify setting of flag that indicates shared object
Add maintainer information

This seems to have disappeared in one of my many edits of this file
when trying to set version number in it automatically.
tutorial: make the copyright notice disappear in the HTML

IMHO it is not useful there.
Merge pull request #189 from andlaus/do_not_list_copyright_header

tutorial: make the copyright notice disappear in the HTML
Merge pull request #188 from rolk/188_maint

Add maintainer information
fixed: remove non-existent files from install list

these were removed in dd43305748b8cdfdfc8caccd95f6a00ad0951aa9
Merge remote-tracking branch 'upstream/release/2013.03' into make-io-subdir
Don't probe for umfpack with cholmod unless latter is found
Changed overlooked include path.