jsamp: note JSAMP update in ttools/topcat change logs

I forgot to do this before the release, so the release change logs
don't mention it.  I'm editing these items back in to the log entries
for the previous version.
table: STIL version to intermediate value 3.0-8+
table: add alternative OnceRowPipe implementation

New class OnceRowPipe2.  This should provide identical behaviour to
OnceRowPipe, but it's implemented using more modern classes.
I wrote it to test something out.  It is not currently used
in any implementation.

For now this class is hidden in the API (it's package-private),
but I'm keeping it here in case OnceRowPipe causes trouble in the future
and I want something to compare it with.
util: use generics for Loader.getClassInstance(s) methods
fits: remove some misleading synchronized declarations

In ColFitsStarTable some ByteBuffer reading implementation methods
were marked synchronized and others were not.  In fact ByteBuffer
access is not thread-safe, so potential multi-thread invocations
must always be synchronized.  They are already so protected, because
the contexts in which they are invoked are already synchronized.
So remove the declarations.
ttools: version number to intermediate value 3.0-1+