#30 More rules

[Aslak]

Rather than have an ignore/accept regexp, then have a
list of rules that are checked in order.

Rule types could be: "RegExp rule","Size rule","Date
rule".

All rule types should have fields for whether the
rule should accept or exclude files/dirs that match
the rule. Additional fields would be:

* A regexp rule would have a field for the pattern

* A size rule would have fields for whether it should
check for whether the size is greater or smaller than
xxx bytes.

* A date rule would have a field for newer/older than
a fixed date