Merge branch 'master' into ng/master

Merge branch 'master' into ng/master

* master:
  post-release: micro version bump (1.13.2a)
  release: stable micro release 1.13.2
  vala tests: skip in a cross compiler setup
  HACKING: miscellaneous fixes, updates and enhancements
  NEWS: minor improvements to wording (about new versioning scheme)
  THANKS: update Akim's e-mail address
  tests: less uses of "make -e"; avoid spurious failures in 'check-cc-no-c-o'
  build: be more respectful of user-specified verbosity
  check-cc-no-c-o: unify initializations in a single place
  check-cc-no-c-o: avoid a spurious failure
  build: fixup for building in a VPATH setup
  Use AC_DEFUN_ONCE to define AM_PROG_CC_C_O
  compile: avoid AC_PROG_CC messy rewrite
  options: tiny simplification in dealing with incompatible versions

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>