templatefilter: add support for 'long' to json()

When disabling the '#requires serve' check in test-hgwebdir.t and running it on
Windows, several 500 errors popped up when querying '?style=json', with the
following in the error log:

    File "...\\mercurial\\templater.py", line 393, in runfilter
      "keyword '%s'") % (filt.func_name, dt))
    Abort: template filter 'json' is not compatible with keyword 'lastchange'

The swallowed exception at that point was:

    File "...\\mercurial\\templatefilters.py", line 242, in json
      raise TypeError('cannot encode type %s' % obj.__class__.__name__)
    TypeError: cannot encode type long

This corresponds to 'lastchange' being populated by hgweb.common.get_stat(),
which uses os.stat().st_mtime.  os.stat_float_times() is being disabled in util,
so the type for the times is 'long' on Windows, and 'int' on Linux.

mercurial/templatefilters.py

@@ -221,7 +221,7 @@ def indent(text, prefix):
 def json(obj):
     if obj is None or obj is False or obj is True:
         return {None: 'null', False: 'false', True: 'true'}[obj]
-    elif isinstance(obj, int) or isinstance(obj, float):
+    elif isinstance(obj, (int, long, float)):
         return str(obj)
     elif isinstance(obj, str):
         return '"%s"' % encoding.jsonescape(obj, paranoid=True)