1. distinguish between Darwin x86 and Darwin PPC
2. lists the "fail rates" for individual client states to allow to
distinguish between download errors, computing errors and aborts
3. optionally list individual "unknown" OS by name
4. optionally list "unofficial" application versions
3. and 4. are probably rather confusing on open-source projects like SETI,
but I found them helpful e.g. on Einstein
svn path=/trunk/boinc/; revision=14169
