Fixes problems with paths containing quotes (sic)

The Windows shell doesn't seem to support single quotes…

Contributed by Dies Koper, Luke Carrier

Change require to require_dependency so SCM classes get loaded on each request in dev mode

It turns out in this case or core patches, unloadable actually breaks in
development mode. Did I already mention that I hate the Rails reloader?

This brings us a reliable filter override until
https://github.com/Shopify/liquid/pull/87 is accepted and
released upstream.

This commit moves the markup caching into Liquid rendering. As
Liquid allows to return different results depending on the environment
(variables, logged user, ...) we only cache the page if it contains
no active content.

Unfortunetely, active content currently also includes the TOC
in wiki pages.

We programmers have a nice new years tradition: We revisit all of our
projects and add 1 to a small number near a "(c)".

-- Volker Dusch
https://twitter.com/__edorian/status/153801913442373633

This is necessary because in Ruby 1.9.3, the behavior of an internal dup of
the array (rb_ary_dup) was changed to always return an array instance, not
an instance of the actual class which it was working on.

Why can't people just stick to what works but instead try to have special
snowflakes everywhere? </rant>

These filters change the implemntation of sub and gsub to use the block method.
This prevents the evaluation of backreferences in the replacement text. See
https://gist.github.com/1491437 for examples.

Also, it allows split to be called without arguments to split strings on
whitespace.

The floated tags (>toc and <toc) are invalid syntax because of the < and >
characters. We transform them to toc_left and toc_right instead.

This is required to retaiun the definition in development mode as the module
is stragely reloaded.

Encloses since date in single quotes. This was causing git to respond with fatal: Unknown Object and preventing revisions from being updated. 

* Won't output errors when the ChiliProject git repo isn't there anymore,
* Works even if not invoked from the ChiliProject root directory,
* Moved the formatting logic to the git call.

Based on a patch by Jean-Philippe Lang.

Based on a patch by Jean-Philippe Lang.