VitaShell Themes: Update and Relocation

As part of a reorganization effort, I have moved all VitaShell themes to the new Downloads section, and removed all the individual VitaShell theme posts. This was done to clear some clutter and provide one location for all the current and subsequent VitaShell themes.

The existence of individual posts is then meaningless.

Furthermore, all themes are now updated for VitaShell 1.98 and all the visual glitches I could notice are gone. If you managed to find a glitch somewhere, please notify me in twitter. (Links in the sidebar)