0.5.2 is now available for download! This is only a bug fix release but it fixes the "add existing file" feature that broke with 0.5.1.
There is no Linux x64 build at this time because my build machine died while building this package. I'll be looking into options to replace this machine but Linux x64 users will have to make due with the x86 Linux release for the time being. I've been having problems with my build machine (since the 0.5.0 release) but this time it looks like it's might be beyond reviving.