[FYI] Merge branch 'maint' into master

[Stefano Lattarini]

commit 84d77cd6e35f66a6bfd5b41a39bb8c2a4f909b6f
Merge: 9cb18f1 1e44f85
Author: Stefano Lattarini <address@hidden>
Date:   Sat Jan 12 13:54:43 2013 +0100

    Merge branch 'maint'

    * maint:
      tests: remove most uses of the AM_PROG_CC_C_O obsolete macro
      coverage: obsolete macro AM_PROG_CC_C_O should cause no warning nor errors
      INSTALL: update copyright years
      ithreads: use runtime (not configure time) detection of perl threads
      copyright: add few missing copyright notices
      maint: files in PLANS are to be exempted from copyright notice
      maint: consistently honor the UPDATE_COPYRIGHT_YEAR environment variable
      copyright: update some copyright years

    Signed-off-by: Stefano Lattarini <address@hidden>