Small ES/CAT fixes

· Added translations for the new fields
· Fixed some spelling mistakes
· Changed where possible english to spanish links.

There is few info in spanish/catalan to change all links to es/cat sources, but when I have time I'll work on the Bitcoin/Peercoin spanish wiki and hopefully all links can be changed then
YouTube video now no longer overlaps the menu.
Merge pull request #40 from boshevski/master

Improved the social icons and the Resources, News and Events pages
Update 404.php

header_index.php was removed with the social icons update #34.
Merge pull request #44 from panupan/patch-1

Update 404.php
Merge pull request #45 from boshevski/master

Sponsorship page banners
Added Sponsor Page
Merge pull request #46 from boshevski/master

Projects page
New Peer4Commit Button
Added Project Page
Fixing Header Link
Merge pull request #25 from mrbickle/master

Small ES/CAT fixes
Allow wider navigation bar for higher screen resolutions.
Update french translation.
Remove strings for nonexistent entry in the menu.
Add strings for new entries in the menu.

A few modifications to try to make strings easier to find/translate:
- Organize the strings in several files (header, main body, footer, etc...).
- Sort the strings by alphabetical order (by language code for each string id, keeping english first as it is the reference string).
Merge pull request #49 from glv2/locale-fr

Update french translation and organize strings.
Merge pull request #48 from glv2/css

Allow wider navigation bar for higher screen resolutions.
Merge pull request #33 from bearbin/patch4

YouTube video now no longer overlaps the menu.
Completed issue #47.
Merge pull request #54 from bearbin/patch6

Completed issue #47.
Improved italian translation