+ default alphaPreconditioner=None --> Use alpha for preconditioner
+ JacobiUpdate is skipped for TPS1(PF)
+ moved stuff between _tpsx.py _intergrator.py tps1.py

+ renamed alphaP --> alphaPreconditioner
+ removed various prints and comments
+ removed gmres restart number 200 in tps1

use with
+ par.QmatType = "staticHouseholder"
+ par.QmatAxis = "e2plus" # for example

+ not clear yet, what mathematical j_cf is exactly for Slonczewski / ZhangLi
+ wait for Michele's input
+ special care has to be taken for hc(v), hc(mOld) if current not time-dependent to be more efficient

Structure:
_magnetostaticField.py: Base class
  - {Stray,Oersted}Field derive from it
_detailsMagnetostaticField.py: static class variables for BEM stuff
  - K operator
  - BEM mesh
  - bemMesh <-> ngMesh mapping

{stray,oersted}Field.py:
  - Derive from _magnetostaticField.py
_details{Stray,Oersted}Field.py: static class variable for FEM stuff
  - forms, preconditioners, solver

- i.e. for strayField, oerstedField or magnetostaticField(=both)
- moved ComputeMaxwell to Magnetization class
- added numthreads to the test files
- added some missing import sys

+ for all tangent plane schemes
+ for TPS2 and TPS2AB the analysis requires Je in C^2([0,T])

+ now they all derive from the same base class
+ was necessary to not initialize numthreads or need mpi
+ additionally commmented out all bounding box (TOECDO) stuff

+ moved all imports from top of files to functions/methods using them
+ using os.environ from within python to set environment variables for interpreter
+ use by: I = Integrator(..., numthreads=42)