Add nofmt_printer to color.py

The current printer always expands on the arguments which is a problem
for strings containing %.

Instead of forcing manual string expansion before printing allow for a
no format printer option which simply accepts and prints the string.

Part of fix for issue #131:
http://code.google.com/p/git-repo/issues/detail?id=131

Change-Id: I08ef94b9c4ddab58ac12d2bd32ebd2c413e4f83b

color.py

@@ -126,6 +126,13 @@ class Coloring(object):
       s._out.write(c(fmt, *args))
     return f
 
+  def nofmt_printer(self, opt=None, fg=None, bg=None, attr=None):
+    s = self
+    c = self.nofmt_colorer(opt, fg, bg, attr)
+    def f(fmt):
+      s._out.write(c(fmt))
+    return f
+
   def colorer(self, opt=None, fg=None, bg=None, attr=None):
     if self._on:
       c = self._parse(opt, fg, bg, attr)
@@ -138,6 +145,17 @@ class Coloring(object):
         return fmt % args
       return f
 
+  def nofmt_colorer(self, opt=None, fg=None, bg=None, attr=None):
+    if self._on:
+      c = self._parse(opt, fg, bg, attr)
+      def f(fmt):
+        return ''.join([c, fmt, RESET])
+      return f
+    else:
+      def f(fmt):
+        return fmt
+      return f
+
   def _parse(self, opt, fg, bg, attr):
     if not opt:
       return _Color(fg, bg, attr)