[impdev] Some http texture fixes

[Thickbrick Sleaford]

Hi Imp-devs,
I pushed a branch with several http texture fixes to github. It would be nice 
if people could test it and review before it is merged (though I am pretty 
confident of the changes in it.)

http://github.com/thickbrick/imprudence/commits/http_texture_experiment

The changes are explained here:
http://redmine.imprudenceviewer.org/issues/652

This is a comparison to the weekly branch this was branched from:
http://github.com/thickbrick/imprudence/compare/f2cf12d6bebd98434a0549f031beaac1ff2200c4...http_texture_experiment

-- 
Thickbrick