[ANN] webgen 1.2.1 - static website generator

## About webgen

webgen is a tool to generate static websites by combining content
with template files. You create one or more template files in which
you define the layout of your page and where the content should go.
After that you create page files in which you only define the
content.

You can use a variety of markup languages like Textile or Markdown or
Haml to define your content and you can add dynamic parts via ERB or by
using webgen tags. This allows the automatic generation of menus,
breadcrumb trails and much more!

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

## webgen 1.2.1

This release brings mainly some overall and specific performance
enhancements. The most benefit comes from caching some often needed
data and optimizing calls to `URI` objects.

However, there is also a specific benefit for those using kramdown and
many predefined link definitions as those will not get cached, too.
Note that this will need at least kramdown 1.3.2 to work!

### Changes

* 1 minor change:

  - Various performance fixes in [Webgen::Node], [Webgen::Path] and
    [Webgen::Context]

* 3 bug fixes:

  - [Content processor erubis] is now compatible to [content processor
    ERB] and therefore a drop-in replacement (which is much faster)
  - Fixed [node finder] 'descendants' filter to take already filtered
    nodes into account
  - Fixed display of path handler names in some error messages where
    class names were shown

Cheers,
  Thomas