Merge branch 'maint'

Merge branch 'maint'

* maint:
  recheck: fix interaction with "make -n"
  vala: avoid potential useless remakes (minor bugfix)
  vala: enhance tests
  recheck: behave better with non-GNU make
  check: separate .log -> .html conversion from core testsuite harness
  docs: deprecate .log -> .html conversion by parallel-tests
  tests: list some forgotten test cases in $(TESTS)
  maintcheck: consistency of list of test scripts
  build: explicitly declare some targets as .PHONY
  maint: remove obsolete/broken maintainer targets
  build: improve silencing of automake build system
  tests: move list of tests in its own Makefile fragment

+ Extra non-trivial edits:

* tests/parallel-tests2.test: Obvious edits to merge the slightly
inconsistent enhancements to coverage done in master with those
done in maint.
* lib/am/check.am (check-TESTS, recheck): Sweeping and rather
complex changes to merge the considerable divergences between
maint and master in a way that is meaningful and, where possible,
retains the semantic changes from both maint and master.