[functions.basic] bugfix
[reductors.linear] bugfix
[install] update distribute in newly created virtualenv

This is required for the installation of recent matplotlib.
[tests] don't consider modules in pymor.playground for auto testcase discovery

I'm assuming that's ok now that one can specify a single grid type to
test.
replaced gram-schmidt by modified-gram-schmidt

Conflicts:

	src/pymor/la/gram_schmidt.py
[defaults] more sensible defaults for gram_schmidt_tol and bicgstab_tol
[la.gram_schmidt] improve logging
[la.gram_schmidt] refactor main loop
[la.gram_schmidt] do not orthogonalize wrt. removed vectors
[la.gram_schmidt] make reorthonormalization configurable
[la.gram_schmidt] move numpy_gram_schmidt and numpy_gram_schmidt_basis_extension to playground
[la.gram_schmidt] make find_duplicates configurable
[la.gram_schmidt] add attribution
[la.gram_schmidt] begin log messages uppercase
[demos] display gram_schmidt log messages in thermalblock demo
[tests] basic pytest setup
[tests] fix grid tests
[tests] comment out non-functional test
[tests] update dependencies
[tests] only consider src/pymortests for test discovery