[ANN] kramdown 1.5.0 released

[Thomas Leitner]

## About kramdown

kramdown (sic, not Kramdown or KramDown, just kramdown) is a *free*
MIT-licensed [Ruby](http://www.ruby-lang.org) library for parsing a
superset of Markdown. It is completely written in Ruby, supports
standard Markdown (with some minor modifications) and various
extensions that have been made popular by the PHP Markdown Extra
package and Maruku.

Homepage for installation instructions and documentation:
http://kramdown.gettalong.org


## kramdown 1.5.0 released

This release brings the addition of Rouge as supported syntax
highlighting engine besides Coderay as well as support for MathML
output in the HTML converter through the libraries Ritex or
itex2MML as alternatives to MathJax.

By restructuring the code it will now be very easy to add other syntax
highlighters or math engines in the future.

Please also note that the old 'coderay_*' options are still supported
but they are *deprecated* as of now. It is recommended to use the new
'syntax_highlighter' and 'syntax_highlighter_opts' options instead.
The latter also take precedence over the former 'coderay_*' options.


## Changes

* 6 minor changes:

- Syntax highlighters are now configurable via the new
'syntax_highlighter' option.
- [Rouge] has been added as alternative to Coderay for syntax
highlighting (requested originally as Pgyments support in [#24] by
Jonathan Martin and then [#68] by Eric Mill and [#141] by Jeanine
Adkisson).
- The `<div>` tag surrounding syntax highlighted code now gets a
class `highlighter-NAME` attached where NAME is the syntax
highlighter used (requested in [#76] by Marvin Gülker)
- Math engines are now configurable via the new 'math_engine'
option.
- A math engine based on Ritex for MathML output has been added
(requested by Tom Thorogood who provided the initial pull request
[#169]).
- A math engine based on itex2MML for MathML output has been added
(requested by Tom Thorogood)

* 2 bug fixes:

- Fixed [#171]: Hard line wrapping in the GFM parser didn't work
correctly when an inline element started a new line (reported by
Zach Ahn)
- Fixed [#173]: The HTML `<button>` element is now recognized as
span-level element (pull request by Morandat)

[#171]: https://github.com/gettalong/kramdown/issues/171
[#76]: https://github.com/gettalong/kramdown/issues/76
[#24]: https://github.com/gettalong/kramdown/issues/24
[#68]: https://github.com/gettalong/kramdown/pull/68#issuecomment-30100236
[#141]: https://github.com/gettalong/kramdown/issues/141
[#169]: https://github.com/gettalong/kramdown/pull/169
[#173]: https://github.com/gettalong/kramdown/issues/173


Cheers,
Thomas