Merge branch 'release/v0.2.0'

* release/v0.2.0:
  polish up release notes
  examples: scalar: a few little cleanups
  removed const keywords in scalar_sweeper; they should be there, no idea why it worked even with them
  more documentation for scalar example; added mathjax directives at multiple points
  improved docu for scalar example; added ** at several points
  extended documentation for scalar example
  docu: extending/fixing/cleaning docu for upcoming release
  some enhancements of the coverage generation script
  fix for aggegrated coverage results
  cmake and tests: enable and provide test coverage analysis
  cmake: add option for GCC profiling
  sweeper: incorporate @memmett's remarks
  exceptions must be thrown to be effective
  some code formatting tweaks
  docu: some docu on IMEXSweeper::predict
  encap: some templatization tweaks
  tests: further tweaking MPI advec test
  Travis: explicitly setting occasions of Travis' notification emails
  QUAD: fixed accuracy of QmatTest
  changelog: Add Dr. Speck/Bacon/Pancetta to contributors.
  high precision test for scalar now running: tolerance set to 5e-12
  removed old test_scalar; now called test_scalar_conv
  renamed test_scalar into test_scalar_conv; added new file that will provide the high precision test suggested by michael
  added tests for clenshaw curtis and equidistant nodes but they are NOT working; not sure why
  tests: mpi-fix for GTest
  tests: using another matcher
  tests: on MPI run do not execute GTest::run() on all ranks
  tests: stupid namespaces...
  tests: advec: using different matcher
  travis: enable APT caching and make tests more verbose
  travis: different repos for different versions
  travis: even more stupid...
  stupidity...
  travis: switch to other Boost PPA and test 1.53 and 1.55
  merged torbjoerns improved test_scalar and added tests for radau nodes: now, lobatto, legendre and radau are tested
  tests: scalar: Yo Dawg, I herd you like better tests
  scalar_test is now running and tests legendre and lobatto nodes
  added some comments to test_scalar
  test_scalar now also checks legendre nodes, but the test with DoubleNear fail, because we encounter better-than-expected convergence. Need a DoubleMore, but I did not get a corresponding matcher to run properly
  test_scalar: computation of convergence rate moved from TEST_P script into ConvergenceTest class ; started to add some lines for legendre node testing (not yet complete)
  run_scalar_sdc now gets and pfasst::QuadratureType argument to specify the type of used nodes
  TESTS: added quadrature test comparing Qmat and nodes
  QUAD: uniform -> Uniform
  QUAD: enum class for quadrature types as well..
  QUAD: changed type to enum class, containing S and Q so far
  Add .dir-locals.el for emacs users.
  tests: examples: scalar: rewamped to be parameterized
  scalar: some further cleanup
  Style.
  doc: Tweak README.md, begin adding notes for v0.2.0 to CHANGELOG.md.
  quadrature: Initialize matrix with zeros.
  imex: Support virtual nodes (0 and 1).
  test_scalar now used DoubleNear and checks directly within loop computing convergence rates
  in test_scalar, should now use size_t instead of int
  removed first version of run_scalar_sdc function from scalar_sdc.cpp; instead, the main routine sets default values and calls the run function with these as parameter
  added a test for the scalar example that verifies convergence orders for up to six lobatto nodes
  updated scalar example to fit into testing enviroment; added test routine for scalar example, but so far without any tests
  examples: scalar: some code cleanup
  cmake: little tweaks on example run targets
  quadrature: Add `pfasst::augment_nodes` and handle `is_proper` flags appropriately.
  scalar: Update to new naming convention.
  cmake: Restore and flesh out comments.
  scalar: Put 3rdpart_INCLUDES back.
  incorporating @memmett's suggestions
  scalar: Don't need FFTW.
  a couple of code formatting tweaks
  pfasst: Add `tag` helper and state V-cycle on finest level.
  interp: Flense.
  interfaces: Split out `restrict_initial` from `restrict`.
  cmake: Cut some comments.
  test: Loosen tolerances.
  tests: Update expected solutions and tighten tolerances.
  mpi_pfasst: Set nsweeps on coarse level to 2.
  pfasst: Fix predictor.
  mlsdc: Add `set_nsweeps`.
  poly_interp: Split `interpolate` and `interpolate_initial` routines.
  interfaces: Add `spread` interface and split interpolation.
  encap_sweeper: Add `spread` and `as_encap_sweeper`.
  tests: Add test_mpi_advection_diffusion.cpp.
  renaming a few variables
  Untabify.
  doc: Fix explanation of `impl_solv`.
  travis: Tidy and add full path for MPI example.
  cmake: Change how we're handling MPI.
  examples: some docu and variable renaming for the AdVecSweeper
  further documentation for interfaces
  sweeper: cleanup of IMEXSweeper
  add UNUSED(expr) makro to denote unused parameters
  sweeper: rename f_solve to impl_solve
  adding 'override' identifier where valid
  sweeper: better names for function evaluations
  code style: whitespaces
  travis: make travis use Ubuntu's libfftw3
  cmake: try find system-wide FFTW3 before self-compiling it
  travis: Echo more compiler info.
  cmake: some more output on compiler selection
  3rdparty: using tar file instead of SVN checkout for GMock
  travis: Punt.
  travis: Another shot...
  travis: Use mpich2.
  travis: Fix 'if' statement.
  reordering tests for examples into subfolder
  different parameters in scalar example
  Untabify.
  cmake: Fix typo.
  pfasst/mpi: Flesh out broadcasting.
  style: Applied astyle throughout.
  encap: Provide default implementation of mat_apply.
  docs: Add troubleshooting.md.
  cmake: add make targets to run compiled examples
  travis: another try on enabling MPI on Travis
  cmake: introducing automatic MPI selection
  controller: Go back to `int` vs `size_t` for level iterator.
  docs: Add troubleshooting.md.
  travis: Use mpic++.
  travis: Take a stab at adding MPICH2 support.
  advection-diffusion: Add MPI-PFASST example (mpi_pfasst.cpp).
  style: Untabify.
  controller: Revert back to `size_t` instead of `int`.
  pfasst: Update loops to use new controller state routines.
  style: Tidy and silence some compiler warnings.
  removed scalar example; to be put in through merge with scalar branch
  scalar example
  pfasst: Get PFASST working.  Needs to be flensed.
  mpi_vector: Call MPI_Wait when doing a non-blocking send.
  interp: Add interp_initial_only flag.
  added a sweeper for the scalar test equation
  mpi/pfasst: Flesh out MPI send/recv.
  send/recv: Add `tag` and `blocking` flags to send/recv.
  poly_interp: Add `restrict_initial_only` flag to `restrict`.
  interfaces: Add `initial_only` flag to `save`.
  controller: Use `int` instead of `size_t` in `LevelIter`.
  DEBUG: echo mag of q in f1eval.
  mlsdc: Fix IMEX sweeper to get MLSDC working again.
  pfasst: Add pfasst.hpp.
  mpi: Add mpi_communicator.hpp and mpi_vector.hpp.
  interfaces: Pass ICommunicator to send/recv.
fix DOI vor v0.2.0