Work on documentation

- work on array doc
- update installation doc (python & mac)
- rewrote the mac install doc with the instruction I used on my new mac.
Fix h5 details

- the read/write of a matrix, motivated by doc example.
- flags : added a macro for a flag
- test of clef : simplify

	modified:   test/triqs/clef_examples/simple.cpp
	modified:   triqs/arrays/h5/simple_read_write.hpp
	modified:   triqs/arrays/impl/flags.hpp
move value_view to draft and cleaning mathlib

- and fix some h5 compile issue in stack
- remove include array_stack in old ctmqc
- removed mathlib

	modified:   ctqmc.cpp
	modified:   ../../../triqs/arrays/h5/array_stack.hpp
	modified:   ../../../triqs/lattice/functors.hpp
	renamed:    ../../../triqs/utility/value_view.hpp -> ../../../triqs/utility/draft/value_view.hpp
	deleted:    ../../../triqs/utility/mathlib.hpp