Merge branch 'maint'

Merge branch 'maint'

* maint:
  depcomp: support tcc (Tiny C Compiler)
  tests: workaround for automatic linker determination and conditionals
  info: allow user to inhibit pruning of '${infodir}/dir'
  vala tests: fix spurious failures with older valac (<= 0.7.2)
  tests: fix a timestamp issue, and other minor buglets
  tests: fix spurious failure with older autoconf
  build: remove duplicated entries in $(TESTS)

+ Extra non-trivia edits:
* tests/link_cond.test: Use 'configure.ac', not 'configure.in'.

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