[Release] Update version information for dune-pdelab-howto 2.0.0-rc1
[Howto] Fix warnings about deprecated LaTeX macros
[Bugfix][Howto] Work around abug in the interaction between KOMAScript and headings

The current version of KOMAScript has a bug when used together with the
headings package. The recommnded fix according to

http://tex.stackexchange.com/questions/166779/koma-script-throws-extra-else-error

is to replace the headings package with the command
\pagestyle{useheadings} as provided by KOMAScript.
[Howto] Fix compilation problem in beamer mode
[Cleanup] Fix trailing whitespace in Howto TeX files
[Documentation] Remove notice to use the release branch of the core modules - 2.3.1 has been released
[Dependencies] Bump version requirements of the core modules to 2.3.1

PDELab doesn't work correctly with the 2.3.0 release of the core
modules, so we better reflect that in the dependency requirements stated
in the dune.module file.
[Documentation] Update release notes and bump version to 2.0.0-rc2
[Documentation] Fix introduction of 2.0 release in RELEASE_NOTES

I messed up when editing the release notes, creating a Frankenstein
text made up of bits that pertained to 1.1 and to 2.0.

Replace that mess with a correct text.
[Documentation] Remove unecessary LaTeX packages.

Make it a little easier to compile the howto...
[Git] Add build-cmake to .gitignore.
[Boilerplate] Make sure to use correct geometry type for all grids
[Buildsystem] Clean up build in boilerplateturial

Both autotools and cmake were set up rather strangely in
boilerplateturial. This patches improves things by

- not requiring ALUGrid to build anymore. Most programs don't even use
  it, and the ones that do fall back gracefully to YaspGrid if
  required.

- removing bogus lists of EIGENPROGRAMS and SUPERLUPROGRAMS in
  Makefile.am.

- including missing flags for UG and ALBERTA in CMakeLists.txt.

Thanks to Adrian for testing the release candidate and reporting the
problem.
[Documentation] Mention dune-typetree source package download location
[Release] Update version information and release notes for 2.0.0
Merge branch 'releases/2.0'

Pull in fixes from release branch

* releases/2.0:
  [Release] Update version information and release notes for 2.0.0
  [Documentation] Mention dune-typetree source package download location
  [Buildsystem] Clean up build in boilerplateturial
  [Boilerplate] Make sure to use correct geometry type for all grids
  [Git] Add build-cmake to .gitignore.
  [Documentation] Remove unecessary LaTeX packages.
  [Documentation] Fix introduction of 2.0 release in RELEASE_NOTES
  [Documentation] Update release notes and bump version to 2.0.0-rc2
  [Dependencies] Bump version requirements of the core modules to 2.3.1
  [Documentation] Remove notice to use the release branch of the core modules - 2.3.1 has been released
  [Cleanup] Fix trailing whitespace in Howto TeX files
  [Howto] Fix compilation problem in beamer mode
  [Bugfix][Howto] Work around abug in the interaction between KOMAScript and headings
  [Howto] Fix warnings about deprecated LaTeX macros
  [Release] Update version information for dune-pdelab-howto 2.0.0-rc1

Conflicts:
	README
	dune.module