RTS: ADC read 'max_loops' reset per card

See merge request cds/advligorts!364

Previously in the adc read function, a slow card would lead to 'max_loops' dropping to 1 and staying there for future cards.
Fast ADCs read after slow ADCs would not have the output data properly decimated.

Adding gaussian noise part

See merge request cds/advligorts!354

Adding Noise module parameter that will allow the designer to specify a  seed in order to re-run with the same RNG, also initializing the RNG with a tsc based seed by default. Updating some language around seeding the noise part.

See merge request cds/advligorts!349

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