Description of the modules, todos, remove unused imports.

Former-commit-id: 8fa256520b1fb3fbb69bc65040b0e541b8c38b97

qpms/modules.rst

@@ -0,0 +1,10 @@
+scattering.py: Scattering in finite lattices.
+modes2d.py TODO: Modes in infinite lattices.
+tmatrices.py TODO: T-matrix creation (loading), (symmetry) operations etc. Perhaps move here some content of qpms_p.py
+lattices2d.py IN PROGRESS: Various 2D lattice generation, lattice type recognition and related functions.
+hexpoints.py: To be obsoleted by more general lattices2d.py.
+scripts_common.py: Argument parsing common to various scripts.
+timetrack.py: Auxilliary module for measuring elapsed time.
+qpms_c.pyx: Cython wrapper for the c code and some miscellanous functions.
+qpms_p.py: Miscellanous functions that have not been moved elsewhere.
+legacy.py: Unused code moved from old versions, should not be imported with qpms. To be removed in the end.

qpms/qpms_p.py

@@ -8,8 +8,7 @@ from scipy.special import lpmn, lpmv, sph_jn, sph_yn, poch, gammaln
 from scipy.misc import factorial
 import math
 import cmath
-import quaternion, spherical_functions as sf # because of the Wigner matrices
+import quaternion, spherical_functions as sf # because of the Wigner matrices. There imports are SLOW.
-import sys, time
 
 """
 '''

qpms/scattering.py

@@ -1,6 +1,15 @@
 '''
 Object oriented approach for the classical multiple scattering problem.
 '''
+
+__TODO__ = '''
+- Implement per-scatterer lMax
+  - This means that Scattering.TMatrices either can not be a single array with a fixed
+    (N, 2, nelem, 2, nelem) shape but rather list of (2, nelem, 2, nelem) with nelem varying
+    per particle or some of its elements have to be unused. Anyways, there has to be some kind of
+    list with the lMaxes.
+'''
+
 import numpy as np
 nx = np.newaxis
 import time