Remove ability to define multiple instance databases because of injection problems

The current ability to define multiple instances of the application running with
different databases has been removed because

1) It opens a massive security hole where it is possible for an attached to write over
different parts of the filesystem

2) We don't normally run multiple instances, and
3) It doesn't save much to have them dynamically pass instance data around

Upgraded to mootools 1.5.0

Allow user to define a debug mode where all the files are uncompressed - otherwise
the javascript is compressed (easier than doing it on a per branch basis as before)