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)
Merge pull request #411 from rolk/411_doc

Reduce amount of boilerplate in Doxylocal