[FYI] Merge branch 'maint' into master

[Stefano Lattarini]

commit e2fd8f5c0c90d9894713e34be7ae8e8774c471da
Merge: d90001e 2d3a2e3
Author: Stefano Lattarini <address@hidden>
Date:   Sat May 4 12:11:40 2013 +0200

    Merge branch 'maint'

    * maint:
      maint: targets and recipes to simplify testing on real-world packages
      build: preparatory refactoring
      build: tiny reduction in code duplication
      make flags analysis: handle more options with args
      make flags analysis: use simpler variable names
      make flags analysis: whitespace changes
      make flags analysis: embed in a subshell
      make flags analysis: be more robust
      make flags analysis: cater to GNU make 3.83 (still unreleased as of now)
      tests: expose weaknesses in make flags analysis
      tests: improve debugging output in checks on make flags analysis
      make flags analysis: refactor, to reduce code duplication
      tests: avoid one tricky use of "make -e"
      cosmetics: remove few trailing whitespace occurrences
      typofix: in NEWS (extra whitespace)
      tests: avoid a spurious error with Solaris make
      subdirs: don't return false positives for the '-k' option's presence
      header-vars: recognize more make flags ('-k' in particular)
      header-vars: simplify how make flags are determined
      tests: remove dead code from t/make-dryrun.tap
      header-vars: new variable $(am__running_with_option)
      tests: expose bug#12554 (false positives for presence of '-k' make option)