When unpacking the tarballs, the time stamps are preserved, but the
access time of the files might be set differently. In addition during
configure Doxyfile is always created. This resulted in some files being
newer than the doxygen-tag in the tarball and triggered building the
documentation. This patch fixes the problem for me by only checking the
modification time and excluding Doxyfile.

The cause for the problem was the introduction of cmake/modules. This caused
the find statement to always print something. This patch simply excludes
cmake/modules from the result with grep -v.

fix the last doxygen fix

some accidential debug statements broke the build for a clean checkout

make doxygen work in out-of-source builds:
extra magic to find the correct doxygen-tag file

[[Imported from SVN: r6872]]

don't try to install doxygen when documentation is disabled

[[Imported from SVN: r6852]]

[[Imported from SVN: r6794]]

always install doxygen files, even if we didn't generate them

[[Imported from SVN: r6759]]

This fixes #803, but leaves us with the ugly situation, that docs in the 
tar balls don't get installed, if doxygen is missing.

[[Imported from SVN: r6435]]

[[Imported from SVN: r6156]]

[[Imported from SVN: r6154]]

[[Imported from SVN: r6133]]

[[Imported from SVN: r5937]]

[[Imported from SVN: r5843]]

[[Imported from SVN: r5815]]

* make distcheck work
* make out-of-source builds for tarballs work
... all this only for dune-common...

[[Imported from SVN: r5811]]

[[Imported from SVN: r5804]]

[[Imported from SVN: r5793]]

- add proper web-install target that seperated recursion and local targets
- move web-install to documentation, so that you can call "make web.install" from top-src
- provide fallback targets, if doxygen and/or wml is missing

[[Imported from SVN: r5792]]

[[Imported from SVN: r5782]]

[[Imported from SVN: r5770]]

[[Imported from SVN: r5756]]

- doxygen/html wasn't properly included
- enable build only if doxygen was found

[[Imported from SVN: r5692]]

[[Imported from SVN: r5663]]

[[Imported from SVN: r5661]]

[[Imported from SVN: r5621]]

* run doxygen.css only if it exists

[[Imported from SVN: r5618]]

[[Imported from SVN: r5615]]

[[Imported from SVN: r5605]]

[[Imported from SVN: r5600]]

[[Imported from SVN: r5559]]

also rerun Doxygen when da "modules" file has changed, as used for example by dune grid do seed the module hierachy

[[Imported from SVN: r5547]]

using the wml templates from dune-web.

[[Imported from SVN: r5529]]

[[Imported from SVN: r5524]]

[[Imported from SVN: r5483]]

[[Imported from SVN: r5220]]

[[Imported from SVN: r5211]]

[[Imported from SVN: r5178]]

* use doxy-header/footer.html only wen building with dune-web
* fix #267

[[Imported from SVN: r5164]]