Merge branch 'develop' of github.com:hpcugent/easybuild-framework into develop
add iterate_step in list of steps to run, and prepare for iteration using handle_build_options_as_lists
specify list of options that can be iterated over, and validate them (equal length of lists)
add unit tests for configure/build/install options as lists
drop newline since it hurts @stdweird eyes, apparently ;)
use getinstance
use isinstance
get rid of hackish iterate_step, adjust get_steps and add substep function handle_iterate_opts instead
fix remarks/bugs
hoist determining of iteration count into a function, since it's needed in two places (easyblock.py and main.py)
fix typo
Merge pull request #549 from boegel/iterate_step

add support for iterating over configure/build/install steps