put module naming scheme in place: only retain 0-9, a-z, A-Z, map everything else to '_' (refs #171)

get rid of getcfg/setcfg, replace updatecfg with cfg.update, replace get_name/get_version/get_toolkit with name/version/toolkit properties

clean up custom sanity_check_step implementations by adding optional argument to sanity_check_step function (refs #267)

split Application into EasyBlock and EB_ConfigureMake, move generic easyblocks to easybuild/easyblocks/_generic_, fix all existing easyblocks (subclass from either EasyBlock or EB_ConfigureMake), rename a couple of things along the way (refs #136, #90)