Feature/update uselatex.cmake to 2.3.0

@robert.kloefkorn I added an auto-detection of in-source builds which disables LaTeX. You might want to give it a try. If it works, we can also back-port the very commit to 2.4.2.

Added 37 commits:

• 7772eaab...c955776c - 31 commits from branch master
• d2961d0b - [cmake] Update UseLATEX.cmake to upstream 2.3.0
• 512f7455 - [CMake] Disable LaTeX for in-source builds
• 0255fba2 - [CMake,cleanup] Whitespace and capitalization changes
• 68d7266b - [CMake] Remove create_doc_install
• f73da4c0 - [CMake] Re-introduce create_doc_install for compatibility
• 4dbe8e23 - [CMake] Adapt dune_add_latex_document to new UseLATEX

mentioned in commit 21db3de6

Status changed to merged

mentioned in issue #36 (closed)

mentioned in issue #41 (closed)

Mentioned in commit 21db3de6

Mentioned in issue #27 (closed)