Improve regexp search for NULL values
Improve regexp search for NULL values

We handle empty text strings as NULL in the database most of the time
(should fix that too :) and this results in, for example, a regexp
search for '.*' will not match anything. To resolve this, we now
COALESCE the column with '' for the WHERE clause of our SQL query which
results in a match.

Part of #48

SpriteLink/NIPAP,garberg/NIPAP,plajjan/NIPAP,garberg/NIPAP,SpriteLink/NIPAP,SpriteLink/NIPAP,SoundGoof/NIPAP,fredsod/NIPAP,SoundGoof/NIPAP,fredsod/NIPAP,ettrig/NIPAP,ettrig/NIPAP,fredsod/NIPAP,bbaja42/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,fredsod/NIPAP,ettrig/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,plajjan/NIPAP,bbaja42/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,bbaja42/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,garberg/NIPAP,plajjan/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,plajjan/NIPAP,plajjan/NIPAP,plajjan/NIPAP,fredsod/NIPAP,ettrig/NIPAP,bbaja42/NIPAP