sK1 0.9.3 release

We have released sK1 v.0.9.3! This is a bugfix release. The major fixed issue is a cairo rendering bug on Intel graphics cards and VirtualBox emulators. Also we have fixed some document rendering issues and implemented 'uninstall' command for setup (important feature for those who install application from source code). Thanks to our new VirtualBox build server we have uploaded binary packages for Ubuntu, Mint, Debian, Fedora, OpenSUSE and Mageia distros. The packages are available on https://downloads.sk1project.net/sk1/0.9.3/.