Add a non-modeling column type, the UUID

New column type UUID.
Parse the Java fixed-format UUID.
Display in browser; export to CSV.
Remove as default-available modeling column from most algos.
Add a generic C16Chunk holding 2 longs, available as vec.at16l() and
vec.at16h() and their usual Chunk equivalents.
PrettyPrinter.uuid(lo,hi) for printing.
Fixed bugs with all the various frame splitter utilities dropping the
"time" value (thus converting a time column into an integer column).
Copy the UUID flag thru as needed.
Cleanup numerous ideaj warnings