configurable name <-> atrribute mappings

configurable name <-> atrribute mappings

This makes the whole application much more flexible. It introduces a new
config file called fields where you can specify which schemas and attribute
names Contagged should use.

This patch is probably not complete, yet and breaks things. It will be
followed up by fixing patches.

darcs-hash:20070301133657-6e07b-208768759179631ef8563b5a738b727f08b82548.gz