Try to explain GSoC and advantages of participating in it better.

Emphasize the different reasons to choose wxWidgets as mentoring organization.
Remove "2013" from the side bar links.

It doesn't really matter for which year these links are if there are no
others.
Add a page about making patches.

Also rearrange the experience section in the application template to make it
less redundant.
Move project pages from year-specific directories to "projects".

This will allow us to reuse them in the next years and also generally makes
sense as the projects themselves are not year-dependent.

Also add more links to the 2013 project ideas page and resort it in rough
order of importance.
Minor updates to webview projects page.

Don't mention the year explicitly.

Add horizontal rules between projects for readability.
Add wxAndroid project page.
Added minimal wxiOS project page.