Merge branch 'develop' into 1781

* develop: (520 commits)
  fix GMP dep in Python 2.7.10 goolf/1.4.10 easyconfig
  fix remark wrt sources
  fix remark
  fix/extend sanity check
  {lang}[goolf/1.4.10] Python 2.7.10
  dcw bumped to 1.1.2 and libxml2 python pound deleted
  bump to 3.7.0 + bump dep versions
  Adding moduleclass
  add missing M4 easyconfig
  add missing 'easyblock' line
  A minor change in sources
  minor style fix
  add missing 'easyblock' lines, fix style issues
  add missing patch file for ANTLR
  add more missing easyblock lines
  add missing 'easyblock' line
  Minor changes in configopts
  add missing easyconfig file
  install qhull.pc via CMake rather than using postinstallcmds
  collapse two patches into one
  ...