API Change! File archive API tidied: CFileList now takes care of removing paths lowering case, finding files, it can hold directory trees and is populated by the filesystem and archives. Archives now inherit it and return a const IFileList pointer rather than implementing each method and requiring special entry types in the API. createFileList works with the virtual filesystem. Separated the mount point stuff from the zip reader to its own files. Added GZIP archive type, fixed problem when loading files without names in gzips. Fixed a crash in the file dialog when the file list was null.

todo: update projects, test properly on Windows and OSX, add #defines for archive loaders

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@2590 dfc29bdd-3216-0410-991c-e03cc46cb475