[linearelliptic.problems.default] added copy ctor
[linearelliptic.problems.OS2014] added first draft to playground
[linearelliptic.testcases.base] guard a warning
fixed some warnings
[linearelliptic.problems.OS2014]
[linearelliptic.problems] added OS2014
[linearelliptic...block-swidg] moved estimator stuff to separate class
[linearelliptic.testcases.base] remember partitioning
[tests.linearelliptic] allow some derived access
[test.linearelliptic-swpdg] make discretization type unique
[tests.linearelliptic-block-swipdg]

* make discretization type unique
* report on partitioning
* add some expected results
[tests] errors_are_not_as_expected is now defined in dune-stuff
[tests.linearelliptic-block-swipdg] added test for several partitions
[tests.OS2014-FVCA7-poster] added