Update to 0.5.0

Changelog:
0.5
- A Template is explicitly disallowed
  from having a url that normalizes to relative outside
  of the root.   That is, if the Lookup is based
  at /home/mytemplates, an include that would place
  the ultimate template at
  /home/mytemplates/../some_other_directory,
  i.e. outside of /home/mytemplates,
  is disallowed.   This usage was never intended
  despite the lack of an explicit check.
  The main issue this causes
  is that module files can be written outside
  of the module root (or raise an error, if file perms aren't
  set up), and can also lead to the same template being
  cached in the lookup under multiple, relative roots.
  TemplateLookup instead has always supported multiple
  file roots for this purpose.
  [ticket:174]

0.4.2
- Fixed bug regarding <%call>/def calls w/ content
  whereby the identity of the "caller" callable
  inside the <%def> would be corrupted by the
  presence of another <%call> in the same block.
  [ticket:170]

- Fixed the babel plugin to accommodate <%block>
  [ticket:169]

0.4.1
- New tag: <%block>.  A variant on <%def> that
  evaluates its contents in-place.
  Can be named or anonymous,
  the named version is intended for inheritance
  layouts where any given section can be
  surrounded by the <%block> tag in order for
  it to become overrideable by inheriting
  templates, without the need to specify a
  top-level <%def> plus explicit call.
  Modified scoping and argument rules as well as a
  more strictly enforced usage scheme make it ideal
  for this purpose without at all replacing most
  other things that defs are still good for.
  Lots of new docs. [ticket:164]

- a slight adjustment to the "highlight" logic
  for generating template bound stacktraces.
  Will stick to known template source lines
  without any extra guessing. [ticket:165]

0.4.0
- A 20% speedup for a basic two-page
  inheritance setup rendering
  a table of escaped data
  (see http://techspot.zzzeek.org/2010/11/19/quick-mako-vs.-jinja-speed-test/).
  A few configurational changes which
  affect those in the I-don't-do-unicode
  camp should be noted below.

- The FastEncodingBuffer is now used
  by default instead of cStringIO or StringIO,
  regardless of whether output_encoding
  is set to None or not.  FEB is faster than
  both.  Only StringIO allows bytestrings
  of unknown encoding to pass right
  through, however - while it is of course
  not recommended to send bytestrings of unknown
  encoding to the output stream, this
  mode of usage can be re-enabled by
  setting the flag bytestring_passthrough
  to True.

- disable_unicode mode requires that
  output_encoding be set to None - it also
  forces the bytestring_passthrough flag
  to True.

- the <%namespace> tag raises an error
  if the 'template' and 'module' attributes
  are specified at the same time in
  one tag.  A different class is used
  for each case which allows a reduction in
  runtime conditional logic and function
  call overhead. [ticket:156]

- the keys() in the Context, as well as
  it's internal _data dictionary, now
  include just what was specified to
  render() as well as Mako builtins
  'caller', 'capture'.  The contents
  of __builtin__ are no longer copied.
  Thanks to Daniel Lopez for pointing
  this out. [ticket:159]


(ryoon)