Bump version number and label.

Set version number to 1.0 since core class AutoDiffBlock is quite well-tested
and documented. Prototype solvers and simulators may not yet warrant that
version number, but are stated to be experimental in the README.
Merge pull request #47 from atgeirr/bump-version

Bump version number and label.
Install header-only pkgconfig file to generic lib/

The previous version assumed that we had libraries, and thus always
installs the .pc file in the multi-arch library directory. However,
we now have modules which does not have a library, but whose header
files still need to be located. Since the lib/ directory is usually
in the pkgconfig search path, it is natural to put them there.
Merge pull request #48 from bska/048_cmake

Synchronise build system with opm-core
Fix convergence failure exception message

The message was a leftover from the ImpesTPFA solver and should
reflect the actual location.

Noticed by: qilicun (Liu Ming)
Fixes: Issue #50
Merge pull request #51 from bska/fix-exception-message

Fix convergence failure exception message