Sanguinololu Case w/cooling for 1.3a

this is a derevitive of http://www.thingiverse.com/thing:9002
i made a few changes :
1. reduced the overall hight.
2. made it for the 1.3a version - has a liitle diffrent dimensions
(size and connectors loacations).
3. made a net for the fan since over time alot of dust comes it - this shuold help a bit.
4. made the snapfit connector diffrently
5. added the option to close with bolts
6. made the hole for the bolts 3mm
7. made the thin wall a bit thincker