templater: add hex filter.

mercurial/help/templates.txt

@@ -106,6 +106,9 b' List of filters:'
 :escape: Any text. Replaces the special XML/XHTML characters "&", "<"
     and ">" with XML entities.
 
+:hex: Any text. Convert a binary Mercurial node identifier into
+    its long hexadecimal representation.
+
 :fill68: Any text. Wraps the text to fit in 68 columns.
 
 :fill76: Any text. Wraps the text to fit in 76 columns.

mercurial/templatefilters.py

@@ -6,7 +6,7 b''
 # GNU General Public License version 2 or any later version.
 
 import cgi, re, os, time, urllib
-import util, encoding
+import encoding, node, util
 
 def stringify(thing):
     '''turn nested template iterator into string.'''
@@ -216,6 +216,7 b' filters = {'
     "person": person,
     "rfc822date": lambda x: util.datestr(x, "%a, %d %b %Y %H:%M:%S %1%2"),
     "rfc3339date": lambda x: util.datestr(x, "%Y-%m-%dT%H:%M:%S%1:%2"),
+    "hex": node.hex,
     "short": lambda x: x[:12],
     "shortdate": util.shortdate,
     "stringify": stringify,