Use a random number generator that we know is predictable.

The previous version used drand48 which is not thread-safe and whose
implementation can, at least in principle, be different on different
systems. The new version is more predictable, using a member variable
and a known random number generator from the BOOST library.
fix second place that uses old random number generator
update test output
Merge branch 'bangerth_make-particle-generation-more-predictable'

(this supersedes pull request #188)

The previous version used drand48 which is not thread-safe and whose
implementation can, at least in principle, be different on different
systems. The new version is more predictable, using a member variable
and a known random number generator from the BOOST library.

Also fix test output related to these changes.
fix test output
Merge pull request #187 from tjhei/fix_test_output

fix test output
Bugfix and additional rotation angle output.
Merge pull request #186 from gassmoeller/gplates_output_fix

Bugfix and additional rotation angle output.
Fix a bug and add a test.
Merge pull request #189 from gassmoeller/fix_adiabatic

Fix a bug and add a test. We had a bug in the initial condition 'adiabatic' that only got triggered if one used a model with the bottom boundary layer parameter set to some value and without adiabatic heating. The temperature difference between model and boundary temperature was calculated wrong in this case. This pull request should fix this bug and add a test for this case.