Merge branch 'master' into ng/master (bug#13928 fixed by this)

Merge branch 'master' into ng/master (bug#13928 fixed by this)

Part of this merge is actually a no-op, since we had already fixed
Automake-NG so that the 'subdir-object' option (enabled by default)
would work when foo_SOURCES contains $(var).

OTOH, even Automake-NG suffered of the bug where built object files,
as well as dependency-tracking makefile fragments, could be placed
in $(srcdir) when a source file was specified as '$(srdir)/foo.c' or
'$(top_srcdir)/bar.c'. See bug#16375 and bug#15293.

* master:
  deps: fix corner-case "make distclean" bug
  compile: don't place built object files in $(srcdir), ever ...
  tests: fix some bugs in an XFAILing test
  deps: 'subdir-object' option now works when foo_SOURCES contains $(var)
  NEWS: fix a typo

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