Specify dir. layout and stylesheets in common templates

These options should be common to all OPM modules to get the same look
for the generated documentation.
Remove options that are stored in the common template

The Doxylocal file now only contains things that are specific to this
project (although most projects still does it like this)
Bugfix: vector was used with size zero.
Merge pull request #412 from atgeirr/fix-rockcomp

Fix bug in RockCompressibility class.
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 #411 from rolk/411_doc

Reduce amount of boilerplate in Doxylocal
Merge pull request #413 from rolk/413_inst

Install header-only pkgconfig file to generic lib/
Bump version numbers.

Since there are a few new APIs and features, but no major changes,
it seems proper to move from 1.0 to 1.1, even though strict
backward compatibility cannot be expected.

Label bumped to 2013.10.
Merge pull request #415 from atgeirr/bump-version

Bump version numbers.