LEes Edwards with dynamic rebuild of comms.
Lees-Edwards docs
Merge remote-tracking branch 'tojb/master' into lees_edwards
Changed test script because of syntax errors.
Changed layered test to be run only if LE is off (otherwise
the verlet update frequency test fails which is to be expected.)
intpbc.tcp is broken by this commit for reasons unknown.

Conflicts:
	src/core/domain_decomposition.cpp
	src/core/global.cpp
	src/core/lattice.hpp
	src/core/utils.hpp
	src/features.def
	src/python/espressomd/__init__.py
Modified some testcases so that they only run if LEES_EDWARDS is not enabled. This is because they check the verlet update frequency and LEES_EDWARDS forces verlet updates every time step, which makes these tests fail.
News update.
Merge branch 'lees_edwards'