Add ZIM format support (issue #267). Now turned on by default for Windows only. Under Linux/MacOS use "qmake "CONFIG+=zim_support"" (liblzma-dev package required. Or take xz 5.0.5 sources from http://tukaani.org/xz/ and compile it).
Zim: Add liblzma.a and it headers for MacOS, turn on Zim support under MacOS by default.
Zim: Split files support
Merge branch 'zim-support'