seed in order to re-run with the same RNG, also initializing the RNG
with a tsc based seen by default. Updating some language around seeding the noise part.

startup sequencer: delay units now delay during shutdown

See merge request cds/advligorts!337

delay units now delay some amount during shutdown.
the delay during shutdown is configured as a separate value from the startup delay

RCG: cherry pick two items from master into branch-4.2

See merge request cds/advligorts!335

Previous code assumed link was top-level, dropping any part of the reference after the second slash.
This led to a link to the wrong subsystem.

Improved error message when linked subsystem is not found in library.

Note that the search code doesn't verify the full path of the link.  If there were another part of the same name
but with different parent subsystems, the RCG would happily link to that instead.  This problem is *not* fixed by this patch.

$bdroot is a reference to the current mdl file.  It's used only in newer (>=2017)
matlab versions.

post process script changed to replace $bdroot with current file name, rather than truncated system name.
Also, a single typo was fixed.

rcgtest: Added some more types to ignore during calculation

See merge request cds/advligorts!334

Cherry picked from master

Six channels are created by the EDCU.  Only three were sent to both EPICS and the data stream.
 * Update the standalone_edcu to export the UPTIME, GPS, and DATA_RATE_KB_PER_S values in EPICS as well.
 * Minor formatting changes as per clang-format run.

Closes #332

Adding error message and catching some errors instead of letting the program segfault

See merge request cds/advligorts!330

awgtpman: shore up synchronization with IOP

See merge request cds/advligorts!329

When waiting for testpoint manager to load.

Automatically trigger burt restore when a snap file is loaded.

See merge request cds/advligorts!328

Several steps were taken to shore up synchronization of awgtpman to the IOP.  These steps do not directly address the crash in issue in #377, but by
blocking execution until the model is fully running, they may prevent the crash from ever happening.

1. Ignore negative card counts from the IOP.  This obviously indicates the IOP isn't loaded.
2. Block execution of a seemlingly loaded IOP until cycle counter is seen to change.  The cycle counter doesn't start updating until the
IOP is fully loaded.
3. Allow up to a minute for an IOP to fully load, then exit nicely.

Changed from using an environment variable to using a function interface for setting sdf_file_loaded

This bypasses the frustrating cases where a snap file (particularly safe.snap) doesn't set the right BURT_RESTORE variable.

changing var to match the expected argument to gainRamp

See merge request cds/advligorts!326

RCG: some $target/chans directories if needed

See merge request cds/advligorts!324

Create chans/ipc/<IFO>.ipc if missing during build
Create chans/tmp if missing during installation

RCG: Modify default safe.snap to include DAC kill bypass time

See merge request cds/advligorts!323

Also, change defaults for DACKILL_PANIC variables to NORMAL, and BPTIME variables to 600 sec.

Backport of MR !320 !319 !316, updates to the slow controls SDF to not constrain monitored PVs to a specific prefix

See merge request cds/advligorts!322

 * Remove the prefix from the parsing of the req file.
 * Add a target to build the sequencer to the cmake, for testing purposes.

Closes #369

awgtpman: removal of old build flags that broak setting testpoints

See merge request cds/advligorts!321

We'd dropped an old build flag that was used to determine the element element size for test point numbers.

The testpoint size reverted from 4 bytes to t2, but only in the RPC definition.  As a result, only the first value in an RPC array of testpoints was in the correct position.  Only one testpoint could be specified correctly per test.

I've checked the rest of the code to make sure this was the only remaining use of the build flags.