Support separate build directories.

The reference to "$(top_srcdir)" was present since commit e186c0a,
but needs to be "$(top_builddir)" in order to support out-of-source
builds.

I'll accept the responsibility for not catching this during review.
Correct a number of lingering white-space issues

This commit adopts the common Automake formatting conventions of
other OPM modules.
Move tests out of the source tree
Use path references from the root of the project

This means that it becomes harder to move this directory around, but
that gain is relatively small anyway. It is however necessary to do
this if we are not going to do a recursive build style.
Import cmake/ from commit 5f82198c in opm-core
Remove opm-core specific customizations
Search and replace opm-core with opm-upscaling

Add dependencies that are specific for this library as well as doing
the textual replacement in the configuration file.
Ignore output from CMake build
Remove remnants of the Autotools build system
Merge pull request #27 from bska/clean-build

Clean build
List files that are needed to build the library

This list will be picked up by the modules at a later commit.
Specify source files explicitly rather than with glob
Various improvements in the build process

Allow uppercase alternatives, fix whitespace bug, allow empty pre-
compiled header, find OpenMP
Only regenerate config var file if actually changed
Remove make execution wrapper
Merge pull request #28 from rolk/028_cmakeupd

Update CMake scripts to commit 11bf7bf3 from opm-core
Remove unused variable from example

The value set to this variable is never used, not even in comments
describing what one could do with it. Thus, it has no value as an
example. I want remove it to avoid the unnecessary warning when
compiling the project (currently the only one).
Merge pull request #29 from rolk/029_zerosatnumcells

Remove unused variable from example
Ignore generated class doc. when building in-tree
Merge pull request #30 from rolk/030_gitignore

Ignore generated class doc. when building in-tree