diff: graduate word-diff option from experimental

diff: graduate word-diff option from experimental

Per 4.6 Sprint notes.

I've also made it gated by "formatchanging" since it could change the output
if we had an option to highlight words without using colors.

--- a/mercurial/configitems.py	Fri Jul 06 12:47:02 2018 -0700
+++ b/mercurial/configitems.py	Sun Jul 08 16:21:26 2018 +0900
@@ -147,6 +147,9 @@
 coreconfigitem('annotate', 'noprefix',
     default=False,
 )
+coreconfigitem('annotate', 'word-diff',
+    default=False,
+)
 coreconfigitem('auth', 'cookiefile',
     default=None,
 )
@@ -399,6 +402,9 @@
 coreconfigitem('diff', 'noprefix',
     default=False,
 )
+coreconfigitem('diff', 'word-diff',
+    default=False,
+)
 coreconfigitem('email', 'bcc',
     default=None,
 )
@@ -512,9 +518,6 @@
 coreconfigitem('experimental', 'evolution.track-operation',
     default=True,
 )
-coreconfigitem('experimental', 'worddiff',
-    default=False,
-)
 coreconfigitem('experimental', 'maxdeltachainspan',
     default=-1,
 )

--- a/mercurial/diffutil.py	Fri Jul 06 12:47:02 2018 -0700
+++ b/mercurial/diffutil.py	Sun Jul 08 16:21:26 2018 +0900
@@ -53,7 +53,6 @@
         'showfunc': get('show_function', 'showfunc'),
         'context': get('unified', getter=ui.config),
     }
-    buildopts['worddiff'] = ui.configbool('experimental', 'worddiff')
     buildopts['xdiff'] = ui.configbool('experimental', 'xdiff')
 
     if git:
@@ -101,5 +100,6 @@
         buildopts['nobinary'] = (not binary if binary is not None
                                  else get('nobinary', forceplain=False))
         buildopts['noprefix'] = get('noprefix', forceplain=False)
+        buildopts['worddiff'] = get('word_diff', 'word-diff', forceplain=False)
 
     return mdiff.diffopts(**pycompat.strkwargs(buildopts))

--- a/mercurial/help/config.txt	Fri Jul 06 12:47:02 2018 -0700
+++ b/mercurial/help/config.txt	Sun Jul 08 16:21:26 2018 +0900
@@ -702,6 +702,9 @@
 ``unified``
     Number of lines of context to show.
 
+``word-diff``
+    Highlight changed words.
+
 ``email``
 ---------
 

--- a/tests/test-diff-color.t	Fri Jul 06 12:47:02 2018 -0700
+++ b/tests/test-diff-color.t	Sun Jul 08 16:21:26 2018 +0900
@@ -304,7 +304,7 @@
   > three of those lines have
   > collapsed onto one
   > EOF
-  $ hg diff --config experimental.worddiff=False --color=debug
+  $ hg diff --config diff.word-diff=False --color=debug
   [diff.diffline|diff --git a/file1 b/file1]
   [diff.file_a|--- a/file1]
   [diff.file_b|+++ b/file1]
@@ -337,7 +337,7 @@
   [diff.deleted|-(to see if it works)]
   [diff.inserted|+three of those lines have]
   [diff.inserted|+collapsed onto one]
-  $ hg diff --config experimental.worddiff=True --color=debug
+  $ hg diff --config diff.word-diff=True --color=debug
   [diff.diffline|diff --git a/file1 b/file1]
   [diff.file_a|--- a/file1]
   [diff.file_b|+++ b/file1]
@@ -384,7 +384,7 @@
   > EOF
   $ hg ci -m 'slightly change utf8 char' utf8
 
-  $ hg diff --config experimental.worddiff=True --color=debug -c.
+  $ hg diff --config diff.word-diff=True --color=debug -c.
   [diff.diffline|diff --git a/utf8 b/utf8]
   [diff.file_a|--- a/utf8]
   [diff.file_b|+++ b/utf8]