Fix issue #15. Package 'path' is not OS aware, while 'filepath' is.

Squashed commit of the following:

commit 50e4ca5d2d1e33d2ddbe73907f51e79f80df2795
Author: Antoine Grondin <antoinegrondin@gmail.com>
Date:   Wed Nov 6 15:23:22 2013 -0500

    Use OS-aware path manipulations, instead of OS-agnostic "path".

commit 170ecdb12c491602e5b8c1d580d5d33545bb4c7a
Author: Antoine Grondin <antoinegrondin@gmail.com>
Date:   Wed Nov 6 14:37:52 2013 -0500

    Use os.PathSeparator for every use of '/'
Add Title and Description to metadata of HTML.
Use cookies to remember language choice. See #14
Add language to base posts configs
Add method to change language cookie See #14

At the language selection screen, the cookie is reset. Add logic to the
index function to set the cookie if either it is not set or if it is set to ""
Minor fix to debug statements.
Fix the templates so that they work with languages.

Fix the links on the language selection template.
Cookies don't work the way I thought they did.

So, referer hacks. Seriously this should be scrutinized. See #14 I guess
Fixes #14. Separate out some functions and go fmt

Turned the validLangInQuery method into an extractLanguage method which
takes a request instead of a string. Created a setLangCookie method to
actually set the cookie.
Ran go fmt on the code.
Merge pull request #21 from uiri/bilingual-uiri

Close #14