Convert `=&gt;` to the more semantic `&rarr;`.

`&rarr;` is defined in the HTML 4 spec [1]:

  <!ENTITY rarr CDATA "&#8594;" -- rightwards arrow, U+2192 ISOnum -->

Don't make these replacements in example Python code:

On Sun, Jan 06, 2013 at 05:47:00AM -0800, Greg Wilson wrote:
> On 2013-01-06 8:37 AM, W. Trevor King wrote:
> > On Sun, Jan 06, 2013 at 05:21:02AM -0800, Greg Wilson wrote:
> > > * Where '=>' appears as a string in a Python program to be printed,
> > > it should be left alone.
> >
> > Oops. Sloppy me not checking all my automatic replacements. How do
> > you feel about replacing the Python occurences with `\u2192'`?
>
> -1: I don't want us to have to explain Unicode escape sequences that
> early in the show.  If we could actually trust all the editors people
> use, and legacy tools like Cygwin's 'cat', to display non-7-bit
> characters correctly, I'd just put the ' →' directly in the source, but
> hey, I'd like a unicorn too...

[1]: http://www.w3.org/TR/html4/sgml/entities.html
2013/01/boot-camp-at-mozilla.html: Fix 'scrips' -> 'scripts' typo
2013/01/ubc-swc-r.html: Fix 'grahpics' -> 'graphics' typo

Also remove the space from '<li> Version'.
CONTRIBUTING.md: Change 'clone' to 'fork' for GitHub duping

This is the lingo that GitHub uses, and for me the instructions read
more clearly with a local clone and a remote fork.
Merge pull request #264 from gvwilson/master

Boot camp pages for everything that's now scheduled.
Merge pull request #265 from wking/mozilla-typo

2013/01/boot-camp-at-mozilla.html: Fix 'scrips' -> 'scripts' typo
Merge pull request #266 from wking/ubc-typo

2013/01/ubc-swc-r.html: Fix 'grahpics' -> 'graphics' typo
Merge pull request #268 from gvwilson/blog

Blogging about upcoming bootcamps
Issue  #187: convert `=&gt;` to the more semantic `&rarr;`.

From wking.
Adding actual EventBrite registrations
Merge pull request #269 from gvwilson/master

Fixing EventBrite registration on various pages
Moved January 31 bootcamp to list of previous bootcamps
Added check-bare to the Makefile for doing an unvalidated build
Merge pull request #267 from wking/blog-contrib

CONTRIBUTING.md: Change 'clone' to 'fork' for GitHub duping
Merge pull request #270 from pipitone/make-check-bare

Added check-bare to the Makefile for doing an unvalidated build
Fixing instructions for GEOMAR boot camp
Merge pull request #271 from gvwilson/master

Restoring material about GEOMAR lost during a merge...
1. Blog post about the Next Generation Sequencing course.
2. Tidying up tabs in previous blog post.
Merge pull request #272 from gvwilson/master

Blog post about Next Generation Sequencing course
Added link to VU Amsterdam bootcamp website on our bootcamp page