Context

This pull request solves:

Modifications

mpirun.py and run.py have been merged. These files were huge copy/paste of each other. The purpose was to be sure that the workspace folder was created by rank#0 process. Now, run.py checks whether MPI is used or not and does what is expected (automatically).
wutils used setand grep unix command to display environment variables. This code has been rewritten in order to work also on windows.
Variables such as OMP_NUM_THREADS or MKL_DYNAMIC are now set to predefined and controlled values if (and only if) they are not previously set by the user. For example OMP_NUM_THREADS is set to 1 if OMP_NUM_THREADS does not appear in the list of environment variables.

The tests named fdtd1d_1c and fdtd1d_1d have been modified in order to:
- compute something even if --nogui is set.
- completely hide matplotlib commands when --nogui is set (these tests failed if they were run in a ssh terminal without X display)

Some old files have been put in a new mirrors/attic folder: imported_10x10.py, imported_30x30.py, loop_old.py, loop_old2.py
Some broken tests have been moved to mirrors/broken: NISP_Leg_cond.py (too old matplotlib), mirrors01.py, mirrors03.py, mirrors_test_battery.py (bad mesh with wrong normals)
A folder named figs has been created for the scripts producing figures for reports: LSP*.py, numpy_matplotlib*
mirrors/mirror_ss.py: the only working model for mirror! It has been cleaned. An "nogui" option has been added in the parameter list. Its defaut size has been decreased.
mirror source code:
- removal of unneeded header
- basic code formatting
- removal of unused code
- additional comments/doc
Tests:
- mirrors02.py has been deleted (same as mirrors/mirror_ss.py and mirrors/tests/test1/simple.py )
- mirrors/tests/test1/simple.py was moved to mirrors/tests
- all loop*.py have been reduced in size so that they run in a few seconds.
- all loop*.py can be run either with GUI or not with the desired result.