.htaccess: File concatenation requires mod_include
.htaccess: Extend the list of forbidden files

Add Emacs auto-save files (http://emacswiki.org/emacs/AutoSave) and
vim swap files (http://vimdoc.sourceforge.net/htmldoc/recover.html)
to the list of forbidden files.

Thanks @feross and @awebdeveloper.
.htaccess: Add Content Security Policy boilerplate
.htaccess: AddCharset & AddType require mod_mime

Documentation: http://httpd.apache.org/docs/current/mod/mod_mime.html
Add `CONTRIBUTING.md` file

Providing the `CONTRIBUTING.md` file alows us to take advantage
of GitHub's UI and prompt contributors to read the repository's
guidelines before creating an issue or opening a pull request:
https://github.com/blog/1184-contributing-guidelines

The `CONTRIBUTING.md` file content is based on @necolas's Issue
Guidelines: https://github.com/necolas/issue-guidelines
expires.conf: remove duplicate .ico cache headers
Don't cache .html or .htm files

Thanks @aitte, ref #133
nginx: change regex patterns to non-capturing for speedup
protect-system-files.conf: use "deny all" for clearer intent when blocking access
nginx.conf: Remove the gzip_buffers directive and let nginx figure it out instead, that way it will align them to CPU cache lines for greater performance
nginx.conf: Make use of the "auto" directive to let nginx spawn as many workers as there are CPU cores
replacing everything with more descriptive comments

for people that don't know what the options do
nginx.conf: protect server against the BEAST SSL attack (ref: http://nginx.org/en/docs/http/configuring_https_servers.html)
nginx.conf: Massively speed up SSL connections by caching the sessions for 10 minutes rather than constantly re-negotiating
nginx.conf: Add support for default SSL certificate served to clients with old browsers
cache-file-descriptors.conf: new feature which greatly speeds up performance on very busy production sites
protect-system-files.conf: clarify why people should be using it
expires.conf: add missing .htc file type
[iis] Fix JavaScript not being gzipped

IIS requires the MIME type of JavaScript set to `text/javascript`
in order for gzip compression to kick in. For further details, see:
http://coderjournal.com/2008/04/iis-7-compress-javascript-gzip/

Fix h5bp/server-configs#45
Ref h5bp/server-configs#141
Remove all white spaces