Added intel & foss toolchains
Merge pull request #940 from hpcugent/develop

release EasyBuild v1.13.0
add commandline override for optarch toolchain setting
added unit test.
fix unit test.
override optarch after arch check
coding by trial and error.
made unittest uglier, but works now. 100%. every time. on my machine.
set module name for toolchain using correct det_full_module_name method, to make it always work with custom module naming schemes
take into account dummy toolchain for which no module name should be determined
fix import in module_generator tests
don't redetermine module name for current toolchain
give proper warning when robot isn't used while it's required
avoid infinite recursion if there's a KeyError in a custom module naming scheme
support separation between module subdir and module name in module naming scheme by extending API for custom module naming schemes
always use full module name in easyblock.py
fix missing import
fix uses of det_module_name in easyblock.py
only check existence for a proper toolchain module name (i.e. a string)
add support in module naming scheme API to specify list of extensions to $MODULEPATH, and generate prepend-paths statements in the module file for them