util: accept "now, today, yesterday" for dates even the locale is not english

Hi there!

Fixed date names are helpful for automated systems. So it is possible to
use english date parameter even if the underlying system uses another
locale.

We have here a jenkins with build jobs on different slaves that will do
some operations with "dates" parameter. Some systems uses English locale
and some systems uses German locale. So we needed to configure the job to
uses other date names.

As this is really annoying to keep the systems locale in mind for some
operations I looked into util.py. It would be helpful for automated systems
if the "default English" date names would even usable on other
locales.

I attached a simple patch for this.

Best regards
  André Klitzing

mercurial/util.py

@@ -1352,11 +1352,11 b' def parsedate(date, formats=None, bias={'
         formats = defaultdateformats
     date = date.strip()
 
-    if date == _('now'):
+    if date == 'now' or date == _('now'):
         return makedate()
-    if date == _('today'):
+    if date == 'today' or date == _('today'):
         date = datetime.date.today().strftime('%b %d')
-    elif date == _('yesterday'):
+    elif date == 'yesterday' or date == _('yesterday'):
         date = (datetime.date.today() -
                 datetime.timedelta(days=1)).strftime('%b %d')