Search for module in suite directory if specified

Instead of having to specify each and every project in a suite such as
DUNE or OPM, allow a root directory for the entire suite to be specified
and then assume that each module is located in a sub-directory to this.

Each individual project can still have its path explicitly specified, if
a special build of those are required.

The suite variable itself will be written to cache by being specified
on the command line. Each individual project directory will NOT be
written to cache, because then we cannot get rid of it by specifying a
new suite directory.
Provide suite info for those not in name convention
Give better diagnostics in case probe fails

The standard argument handling report which item that failed
(_INCLUDE_DIR, _LIBRARY og HAVE_) but it doesn't provide information
about the root that was used to search for these. Given that we now
automatically search a lot of other places, the _ROOT variables should
be reported before the error is raised.
Allow packages to be installed directly in suite dir

Let us specify e.g. --with-dune=/usr, so that the _ROOT variable is
set to e.g. /usr/dune-common, but then backtrack to the parent directory
again if we don't find anything there and search directly in suite dir.
Also look in corresponding build-dir as ourself

If we are building in a sub-dir to the source tree, guess that a
dependent module is also that, and that the directory that is given
is for the suite, not for the project alone.
Teach configure wrapper to know about modules
Remove exclusion erroneously copied from opm-core

The exclude statement correctly belongs in the Doxylocal file, fixed
in commit 3c7594d in opm-core. However, this file was copied from that
project before the fix.
Add more support for configuring MPI

Handles options --enable-mpi and --with-mpi-prefix for compatibility
with other autotools projects which uses these settings to tell the
build system where the local MPI library is.
Remove trailing empty element on dependency list

An extra semi-colon had snuck in here which caused the project to be
dependent on a module called "", which of course failed further down
the line.

This error was previously undetected because we didn't have anything
that depended on opm-upscaling.
Detect empty elements in dependency list

These errors are usually an extra trailing semi-colon, which is easy
to put in there for symmetry with the other lines. Give a warning on
this but proceed with the build as usual afterwards.
Allow user to override our non-standard defaults

CMake loads option defaults from the platform file and then usually
proceeds to write these to the cache, so it is not possible to see
if an option was specified by the user, or was the default.

By setting CMAKE_NOT_USING_CONFIG_FLAGS, we regain control over the
options and can then set this to what we think is suitable, provided
that the user hasn't specified something for us.
Allow whole program optimization to be switched off
Minor refactoring to make code more readable
Report target architecture compiling for
Build release library by default

If you just download the source, compile and install, you get the
release library. Users who want to develop the code, must do setup
in their environment.
Quote possibly empty variable to avoid error message

On RedHat 6.4 workstation the module doesn't find the necessary system
information, and gives an error message when the last parameter to the
string function is not present.
Read /etc/system-release if others not parseable
Corrected mismatched if-else-endif arguments
Probe for library without using STL

If dune-grid has been compiled with _GLIBCXX_DEBUG, linking the test
program will fail since probing doesn't get the flags that are specified
for the main project, and thus configuration halts. Instead, we use a
smaller test program which doesn't need proper STL linkage to compile
and link.
Merge pull request #15 from rolk/015_cmake

CMake rollup