Various fixes and small features

- support for floating point attribute type
- treat resource violation kill as job abort
- correctly send information about job kill between slave<->master nodes
- new resources "cpu_performance" (node), "fairshare" (job)
- new node configuration option cpufactor (float type)
- cross-server shadow jobs are deleted when the real job is purged
- cross-server shadow jobs now report state "X"
- multiple memory leak fixes (scheduler, server, lib)
Version bump