mamewah filter list (.ftr) format
=================================

section desc
------- ----
1	filter type?  (emu-0.ftr = 1, emu-n.ftr = 2)
2	year
3	manufacturer
4	driver?
5	display type
6	screen type
7	controller type
8	driver status
9	colour status
10	sound status
11	category



section split by blank line

each entry is 2 lines:
* line 1: item to filter by
* line 2: True / False

