Merge branch 'ng/distdir-refactor' into ng/master

* ng/distdir-refactor:
  [ng] dist: optimize calculation of list of distributed file
  [ng] dist: rename some non-public vars to make clear they are internal
  [ng] dist: strip duplicates from dist files at make (not automake) runtime
  [ng] dist: simplify VPATH handling

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

diff --cc Makefile.am
Simple merge

diff --cc NG-NEWS
index 025ad2a1a79b3246c4fc3a713524440b2a060e2d,78ab1c26b96952cec00d041182ff3f65e56a25ca..49c16ea34c844577b719637af19474a50c47cb56
--- 1/NG-NEWS
--- 2/NG-NEWS
+++ b/NG-NEWS
@@@ -99,37 -104,21 +99,52 @@@ Parallel testsuite harnes
    work as expected:
      TESTS = $(wildcard $(srcdir)/t[0-9][0-9]*.sh)
  
 +Pattern rules and suffix rules
 +==============================
 +
 +* Old-fashioned suffix rules are not supported anymore; Automake-NG will
 +  error out if you try to use them.  Use pattern rules instead, as
 +  advised in the GNU make manual itself.
 +
 +* The .SUFFIXES: special target and the SUFFIXES special variable are
 +  not supported anymore either; Automake-NG will error out if you try
 +  to define them.
 +
 +* To retain support for user-defined file extensions in the '_SOURCES'
 +  variables (see "Handling new file extensions" in the Automake manual),
 +  Automake-NG still tries to parse and understand suffix-based pattern
 +  rules.  So, an usage like:
 +   
 +      SUFFIXES = .baz .c
 +      .baz.c:
 +              cp $< $@
 +      foo_SOURCES = foo.c bar.baz
 +      DISTCLEANFILES = bar.c
 +
 +  which was valid with mainline Automake, should be translated for
 +  Automake-NG as:
 +
 +      %.c: %.baz
 +              cp $< $@
 +      bin_PROGRAMS = foo
 +      foo_SOURCES = foo.c sub/bar.baz
 +      DISTCLEANFILES = bar.c
 +
+ Distribution
+ ============
+ 
+ * "Bare" wildcards are not usable anymore in $(EXTRA_DIST):
+ 
+      EXTRA_DIST = $(srcdir)/doc/*.txt  # This won't work anymore.
+ 
+    You'll have to use the $(wildcard) GNU make builtin instead, as in:
+ 
+      EXTRA_DIST = $(wildcard $(srcdir)/doc/*.txt)  # Good.
+ 
+    or even (for a better support of VPATH builds):
+ 
+      EXTRA_DIST = $(wildcard doc/*.txt $(srcdir)/doc/*.txt)  # Better.
+ 
  Miscellaneous
  =============
  

diff --cc automake.in
Simple merge

diff --cc t/pr2.sh
Simple merge