[la.interfaces] some docu in VectorArray
[algorithms.basisextension] add pod_basis_extension
[algorithms.basisextension] add documentation
rename VectorArray -> VectorArrayInterface

Conflicts:

	src/pymor/algorithms/ei.py
	src/pymor/discretizations/nonlinear.py
	src/pymor/operators/basic.py
	src/pymor/operators/ei.py
tmp
parabolic2 start
fixes a couple of import problems
fixes a couple more init problems
instationary thermalblock example, now working (run parabolic2.py in pymor/playground/demos)
minor changes, fixed some errors
new instationary thermalblock demo using RB
Merge branch 'parabolic_fubar' of https://github.com/kirstenweber/pyMor into parabolic_fubar

Conflicts:
	src/pymor/discretizations/linear.py
	src/pymor/discretizers/__init__.py
	src/pymor/discretizers/parabolic_cg.py
minor changes and cleaning up