MapR compatability

[John Vines]

So I finally got around to testing MapR (well, finally got it running).
Gave RC4 a test run and, after seeing the stack trace, not surprised it
broke in HadoopLogCloser.close(). IllegalStateException gest thrown from
line 54 due to the filesystem being of type com.mapr.fs.MapRFileSystem. At
this point, I think this should be considered an acceptable break and
something we shoudl try to resolve first thing for 1.5.1. Thoughts?