Truncate post slugs when importing from Tumblr.

Fixes #481.
No need to have a variable assignment, especially if it has the same name as the method parameter.
fix issue 457: Custom destination in _config.yml causes jekyll server to auto-regenerate continuously
Remove deletion of dot files on cleanup.

This is a potentially very dangerous action that's impossible to test that it's correct.
If the '..' check line ever disappears, even running the tests will start deleting
everything accessible on the person's computer.

All dot-files that are generated are already known by Jekyll as either a static file or
a page (yaml front matter), only remove those files.
Add checks to prevent accidental deletion of the source directory
Added path in url.

Page#dir was returning the wrong dir ('/') for pages in directories.
Front-matter should be at start of file

It's the theme of the moment ; regexp checking.

Just in case we have two line start with --- in the file, we want to
make sure it's not interpreted as a front-matter.
make yaml parsing errors more informative
pygments options for pygments.rb
Update redcarpet support to version 2
Better error reporting on Liquid exceptions
Added a configuration variable: keep_files (default: ['.git']), based on this pull request: https://github.com/mojombo/jekyll/pull/556
removed puts
Look for plugins under the source directory

When generating the site, Jekyll will now look for plugins under the
source directory by default. The plugin location can still be changed in
_config.yml
faster_lsi: Massively accelerate LSI performance.

Currently, Classifier::LSI rebuilds the index every time an entry is
added.  This runs into massive performance overheads on my website;
theoretically, disabling automatic index rebuilds, and explicitly
rebuilding the LSI index at the end of the LSI repopulation should
speed things up nicely.

As a side note, here, I use pandoc-ruby to provide a more featureful
Markdown transformer, so be mindful that the numbers I quote here have
artifically imposed I/O overheads.

With just the 76 posts I wrote this year (abysmal, I know), I come up
with the following figures:

    Without faster_lsi:
      jekyll --lsi  16.91s user 0.88s system 97% cpu 18.302 total
    With faster_lsi:
      jekyll --lsi  2.72s user 0.77s system 88% cpu 3.940 total

With 109 posts, we begin to see even better improvements:

    Without faster_lsi:
      jekyll --lsi  51.00s user 1.47s system 98% cpu 53.060 total
    With faster_lsi:
      jekyll --lsi  5.04s user 1.12s system 91% cpu 6.735 total

At this point, we begin to see I/O overheads being slower than LSI
when faster_lsi is active.  I call that fairly conclusive.  But wait,
there's more.  I have 273 posts lying around... I wonder what happens
if I feed them all in.  With faster_lsi, it was nice and clippy.
Without it, I simply gave up, and went and refilled my cup of tea.
And it was still going.

    Without faster_lsi:
      jekyll --lsi  1277.86s user 10.90s system 99% cpu 21:30.29 total
    With faster_lsi:
      jekyll --lsi  34.62s user 4.43s system 96% cpu 40.430 total

That is, in anyone's books, a major improvement.  Note, however, that
I don't know just how well this will perform with `jekyll --auto`
because I don't know how it does the LSI rebuilds.  I _think_ (but
please, don't commit me on this) that the LSI is rebuilt every time
Jekyll picks up a file change.

So, all up, the performance improvement is massive, and scales
depending on how many files you have.  At the last point, the
improvement is just on 3200%.

A more optimal solution would be to cache the LSI index and/or content
data somehow.  I'll leave that to when faster_lsi takes over ten
minutes to run.
Making sure errors don't halt the import.

Wrapped file operations in a begin/rescue block.
Update pygments.rb version
Only pass first class to Pygments

This prevents an exception if something like the following is used:

~~~ {foo bar}
some code
~~~
Convert slashes in titles to dashes when migrating from WordPress

When a post has a title that contains a slash, such as 'This is my cool
blog post part 1/2', convert the slash to a dash so that the post
filename is created correctly.

Fixes issue #680
Add license to gemspec