[config.opts] added -release
[config.opts] default to debug without postfix
[config.opts] fixed debug ones^^
[external-libraries] updated alugrid url
Albrecht -> Schindler
Merge remote-tracking branch 'origin/master'

Conflicts:
	external-libraries.cfg
	opts/config.opts.clang
[external-libraries] use -Wno-dev
[dune-fem-localfunctions] removed
[configs] added master
[config.opts] use clang and clang-release from configs
[external-libraries] updated separator
[demos] updated separator
[opts] updated CXXFLAGS

* removed outdated DUNE_STUFF_FUNCTIONS_TO_LIB
* added DUNE_STUFF_TEST_MAIN_ENABLE_INFO_LOGGING=0
Merge remote-tracking branch 'origin/master'
[dune-stuff] updated master
[local.bin] updated master
[configs] updated master
[dune-gdt] updated master