Indent file lists using <tab> rather than <space>

This is the common convention throughout all OPM modules' CMake-based
build systems.
Merge pull request #9 from bska/master

Unify indentation style in CMakeLists_file.txt
Require the newer 3.1 version of Eigen
Allow user to specify path to Eigen3 library

By setting EIGEN3_ROOT, we can point directly to the path of the
library checkout we want to use. No other searching will then take
place.

Notice that if you have found an Eigen3 installation in a previous
configure, it will not find a new version even if you introduce the
EIGEN3_ROOT variable!
Allow mixed case name in variable (as for package)

Since the package is named Eigen3 (in mixed case), we should allow
for the variable to be named this way, too.
Use standard code to handle not found case

Instead of setting EIGEN3_FOUND ourselves, rely on the standard method
to check arguments and raise an error if not found.
Search common suffixes for include files

This allows us to set e.g. -DEIGEN3_ROOT=/usr/local, and have the
files actually be located in /usr/local/include/eigen3
Merge pull request #11 from rolk/011_eigen

Set path to Eigen3 directory with -DEIGEN3_ROOT=
Use the shared_ptr<> from Boost.

Not all implementations support the TR1, and if they do, the type
might not be in a namespace called std::tr1 .  Favour the
implementation from Boost for reasons of portability.

This is inspired (and necessitated) by commit OPM/opm-core@68eb3fb
which, incidentally, cleaned up some header pollution on which we
inadvertently depended.
Merge pull request #12 from bska/non-tr1

Use the shared_ptr<> from Boost.
added: download and build eigen3 from git if not found on system
Exclude examples/sim_simple.cpp if UMFPACK is unavailable

Not all systems provide UMFPACK so even if Eigen provides the required
bindings, we should not assume that the underlying library and/or
headers are available.  Currently, only examples/sim_simple.cpp uses
UMFPACK unconditionally, so the simplest solution is to exclude that
example unless UMFPACK is available.
do use eigen's umfpack support anymore

use BiCGStab instead. it might be slower, but at least it is always
available...
Merge pull request #14 from akva2/eigen3_external

added: download and build eigen3 from git if not found on system
Merge branch 'master' into optional-umfpack

Conflicts:
	CMakeLists.txt

Import akva2's modified Eigen support.
Fix mismerge in commit b54df70.

We lost the SuiteSparse detection.
Merge pull request #15 from bska/optional-umfpack

Exclude examples/sim_simple.cpp if UMFPACK is unavailable
Merge remote-tracking branch 'andlaus/no-umfpack' into optional-umfpack
Use UMFPACK solver if available in sim_simple.cpp.

Fall back to Eigen's BiCGSTAB solver if UMFPACK is not available.  The
BiCGSTAB is built into Eigen and consequently always available when
Eigen is found.
Merge pull request #17 from bska/optional-umfpack

Use UMPACK only if available