exclude debugallocator.cc from doxygen documentation

[[Imported from SVN: r7019]]

add documentation for allocators

[[Imported from SVN: r7018]]

[[Imported from SVN: r6988]]

[[Imported from SVN: r6872]]

[[Imported from SVN: r6832]]

[[Imported from SVN: r6794]]

[[Imported from SVN: r6776]]

[[Imported from SVN: r6772]]

[[Imported from SVN: r6770]]

In particular, the search gets faster _because of_ the use of ls,
not _despite_ of it.

[[Imported from SVN: r6769]]

Add DUNE_DEPRECATED_MSG() to the predefined macros for Doxygen, otherwise it gets confused and messes up with \copydoc.

[[Imported from SVN: r6768]]

Add DUNE_DEPRECATED_MSG() to the predefined macros for Doxygen, otherwise it gets confused and messes up with \copydoc. 

[[Imported from SVN: r6767]]

[[Imported from SVN: r6762]]

[[Imported from SVN: r6686]]

[[Imported from SVN: r6656]]

 documentation besides doxygen can be installed.
- Make sure we install under ${CMAKE_INSTALL_PREFIX}. Therefore
  we must provide the absolute path to our custom install script.
- Include DuneDoc at toplevel and let create the doc target. Thus
  we can use its macros all over the place.

[[Imported from SVN: r6626]]

Removed UseDoxygen.cmake as it does not seem to fit our needs.

BTW: Welcome to the CMake hell! It exists, I have experienced it!

[[Imported from SVN: r6624]]

[[Imported from SVN: r6623]]

Doyfile.in needs to be generated.

[[Imported from SVN: r6622]]

[[Imported from SVN: r6620]]

Right now only the buildsystem documentation is built.

[[Imported from SVN: r6619]]

[[Imported from SVN: r6616]]

[[Imported from SVN: r6605]]

[[Imported from SVN: r6604]]

ISSUES:
- Only works for out of source builds
- We will probably run into issues on non-unix platforms
- Is the licence compatible with ours?

[[Imported from SVN: r6603]]

The documentation is still not built and therefore not installed

[[Imported from SVN: r6602]]

[[Imported from SVN: r6585]]

exec, module/only, resume/skipfirst and configure caching.
Clarified paragraph about Extra-Suggests.

[[Imported from SVN: r6584]]

[[Imported from SVN: r6583]]

[[Imported from SVN: r6582]]

[[Imported from SVN: r6479]]

[[Imported from SVN: r6478]]

"add sections on dune-specific AM_CONDITIONALS (thanks to Dan)"

[[Imported from SVN: r6477]]

[[Imported from SVN: r6476]]

[[Imported from SVN: r6475]]

[[Imported from SVN: r6409]]

[[Imported from SVN: r6408]]

[[Imported from SVN: r6404]]

[[Imported from SVN: r6360]]

[[Imported from SVN: r6342]]