With foreign types we can no longer generate default initializers
in a portable way, as was done previously (in reentrant mode).
We now leave off initializers from the UserVar struct and instead
initialize the members one by one (using memcpy) from statically
initialized single values.

We issue a warning message in this case, since this is most
probably a logical error in the SNL program.

It is friendlier to just go on than to let the program hang.
Note that this is still a user error and a message is issued
to indicate it.

Must not epicsEventSignal when epicsEventTryWait returns
epicsEventWaitTimeout, since this means we have not yet been called
back by CA. This bug could lead to pvGet/PutComplete erroneously
returning TRUE even though the callback did not yet arrive.

Not all C compilers allow empty struct definitions. This fixes
a problem when building on solaris-sparc.

Installation.txt says you can check out the darcs repository like this:

  darcs get http://www-csr.bessy.de/control/SoftDist/sequencer/repo/<branch>

It then lists the branches, which to me should be the exact string I
need to use in place of "<branch>" to construct a valid URL for the
repository I want, but it's not.  Fix this by replacing the space in the
listed branch names with a dash.

This fixes a build error with older base releases.

Program parameters are now consistently referred to as such. The term
"macro" is used only for C preprocessor macros. Wordings were adapted
accordingly and some related improvements made.

This will (hopefully) make future upgrades easier.

See http://www3.sqlite.org/cgi/src/finfo?name=tool/lemon.c
The latest change in this version is from 2012-08-20.

- make clear that you can reference foreign entities
  directly in action statements w/o recourse to escape syntax
- explain why and how to avoid #include and other CPP directives
  in multi-line escaped code blocks

This prevents a race condition resulting in a crash when the program
shuts down and deletes mutexes etc before the callback has issued its
final ss_wakeup call.