added ability to scale background image, taken directly from augusto
Added initial version of dashed and dotted cell borders.
Fixed syntax error.
Fixed typos.
Fixed single value not working.
Fixed problems with array length when checking border lines.
Fixes for dotted border.
Added page to manual showing how to use border lines.
Added specs for cell border lines.
Move PRAWN_VERSION constant into file

Silences constant redefinition warnings. Closes #352.
fix this font spec to check the correct encoding on M17N aware VMs

* I'm not particularly familiar with font related sections of prawn, so
  someone please correct me if I'm wrong
* Prawn::Font::TTF#encode seems to convert utf-8 strings into the
  subset specific encoding, meaning the returned strings will be tagged
  as 'binary'
* Ruby 1.9.3p194 seems to be stricter than earler releases of the 1.9
  series when comparing strings of different encodings
* See GH#357 for more detail
set default external encoding for the manual.
Keep outline when :optimize_objects => true
Merge pull request #358 from boutil/master

Set Encoding.default_external to UTF-8 to build manual on systems with non Unicode locale
Add :before_rendering_page callback to specify page styles
Change before_rendering_page to slightly cleaner block API
Merge pull request #362 from sos4nt/outline2

Keep outline when :optimize_objects => true
Add example bug in PNG alpha channel unfiltering

The mathn library changes Fixnum division to return a
rational instead of a floored int. The `PNG#unfilter_image_data`
function relies on an implicit flooring.
Fix implicit flooring bug in PNG alpha channel unfiltering

Explicitly floor Fixnum division in `unfilter_image_data`.

The `mathn` library redefines division to be more precise rather than
flooring automatically. There's no downside to explicit flooring here,
and now it works even with that library included.
Merge pull request #363 from scpike/master

Fix implicit flooring bug in PNG alpha channel unfiltering