This is a gnu extension that enables argument checking for
user defined printf-like functions.

Particularly, use unsigned for syntax node types, since we use
bit masks to represent sets of those types. This is necessary
because (at least in C99) shifting a 1 into the sign bit is
undefined (and we use all the available bits).

removed keck examples, they did not build since a header file is missing and use the KTL backend which is no longer supported

Now, if you do pvSync(x,ef), where x is an array for which the elements are
individually assigned to a separate PVs, then all the elements get synced
with the event flag, just like if you use the sync clause.

The messages about not yet connected/monitored channels appear now
at a more user-friendly rate, stabilising at 1 per hour.

Thanks to Wesley Moore (JLAB) for coding up this example.

With parallel make (-j) the snl.c and snl.h targets were built
twice which could cause building to fail. With the changed rules
I ran into a make bug and had to add an empty recipy where it
should not be needed. Also needed to work around a bug in the base
rules (no explicit rule exists that generates the .d files).

test/compiler/namingConflict.st demonstrates a case where
without the added state set number a naming conflict arises.