#989 Add support for Inno Setup compression

[Jonas]

Add support for Inno Setup compression, It use file header id "zlb"
"ZLIBID: TCompID = 'zlb'#26;" <- from Struct.pas

Link to source code: http://www.jrsoftware.org/isdl.php

[Synetech]

[Raccoon]

what he said. it would make extracting many installer packages for windows possible, to avoid adware.