More OSNetworkSystem cleanup.

Handle select(2) errors by throwing exceptions from native code (which is
simpler and provides more useful detail messages).

Factor out exception throwing commonality. This is probably ready for JNIHelp.h
now.

Remove sockSelect. Simplify selectWait by observing that it's only ever called
with a "read" fdset.

Remove a little more SOCKERR_* cruft.

Remove a few unused #defines.
2 files changed