Merge branch 'ng/var-simplify' into ng/master

* ng/var-simplify:
  [ng] cosmetics: avoid redundant use of '&' in subroutine calls
  [ng] rename: define_pretty_variable -> define_cond_variable()
  [ng] cleanup: prefer 'define_variable' over 'define_pretty_variable'
  [ng] refactor: change signature of 'define_variable()'
  [ng] vars: get rid of VAR_ASIS / VAR_PRETTY distinction
  [ng] vars: keep track of conditionals in appended values and comments
  [ng] vars: simplify logic for appending conditionally
  [ng] VarDef: store comments and values as a perl array
  [ng] refactor: support comments only for VarDef, not for ItemDef too
  [ng] tests: Automake should let us append to undefined variables (someday)
  [ng] tests: spy behaviour of '+=' with GNU make
  [ng] vars: get rid of VAR_SILENT type
  [ng] vars: get rid of VAR_SORTED type
  [ng] cleanup: remove unused private variables in Automake::Variable

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

diff --cc Makefile.am
Simple merge

diff --cc automake.in
index 27bec1846423284c01419446b3c1330291714549,d502506f89a66c8f87c5f33ccb168968c91e0bc9..1bf6a241d767af09df290e0da811e4f6a72db6d5
--- 1/automake.in
--- 2/automake.in
+++ b/automake.in
@@@ -3975,7 -4007,7 +3968,7 @@@ sub handle_configure ($$$@
          push @config_h, "\$(top_builddir)/$out";
        }
      }
-   define_variable ("AM_CONFIG_HEADERS", "@config_h", INTERNAL)
 -  define_variable ("CONFIG_HEADER", INTERNAL, @config_h)
++  define_variable ("AM_CONFIG_HEADERS", INTERNAL, @config_h)
      if @config_h;
  
    # Now look for other files in this directory which must be remade

diff --cc lib/Automake/Rule.pm
Simple merge

diff --cc lib/Automake/Variable.pm
Simple merge