extdiff: made it less chatty in non-verbose mode

Made the status info only display in verbose mode since most hg commands aren't so chatty. This also makes it cleaner for other extensions to call extdiff.

hgext/extdiff.py

@@ -63,9 +63,8 b' def snapshot_node(ui, repo, files, node,'
     dirname = '%s.%s' % (dirname, short(node))
     base = os.path.join(tmproot, dirname)
     os.mkdir(base)
-    if not ui.quiet:
-        ui.write_err(_('making snapshot of %d files from rev %s\n') %
-                     (len(files), short(node)))
+    ui.note(_('making snapshot of %d files from rev %s\n') %
+                 (len(files), short(node)))
     for fn in files:
         if not fn in mf:
             # skipping new file after a merge ?
@@ -90,9 +89,8 b' def snapshot_wdir(ui, repo, files, tmpro'
         dirname = "root"
     base = os.path.join(tmproot, dirname)
     os.mkdir(base)
-    if not ui.quiet:
-        ui.write_err(_('making snapshot of %d files from working dir\n') %
-                     (len(files)))
+    ui.note(_('making snapshot of %d files from working dir\n') %
+                 (len(files)))
     for fn in files:
         wfn = util.pconvert(fn)
         ui.note('  %s\n' % wfn)

tests/test-extdiff.out

@@ -1,9 +1,5 b''
 adding a
-making snapshot of 0 files from rev 000000000000
-making snapshot of 1 files from working dir
 Only in a: a
-making snapshot of 0 files from rev 000000000000
-making snapshot of 1 files from working dir
 diffing a.000000000000 a
 hg falabala [OPTION]... [FILE]...
 
@@ -26,14 +22,10 b' options:'
  -X --exclude  exclude names matching the given patterns
 
 use "hg -v help falabala" to show global options
-making snapshot of 1 files from rev e27a2475d60a
-making snapshot of 1 files from rev 5e49ec8d3f05
 diffing a.e27a2475d60a a.5e49ec8d3f05
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 1 files updated, 0 files merged, 1 files removed, 0 files unresolved
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
-making snapshot of 1 files from rev 5e49ec8d3f05
-making snapshot of 1 files from working dir
 diffing a.5e49ec8d3f05 a
 diff-like tools yield a non-zero exit code