Fix for Frequency bugs and some code cleanup

Attached is a fix for the Frequency bugs and some code cleanup.

Fixes for:
#815106: Use spaces instead of tabs in code

#320067: Splash turning off doesn't turn off
#737196: "Never/Do Not Display" still displays
#775810: Daily/Weekly frequencies only show once

Rewrote the frequency logic so that never/once/daily/weekly/always work as intended.

I've also changed the administration page forms so that they will work correctly with the Domain Access module.

I've attached the full files for splash.module and splash.admin.inc instead of a patch as every single line in both of those files was touched (for code cleanup #815106).

Please test it out, seems to be working correctly for me.