rcg: Moved sequence check into /src/python dir.  Improved sequence error message.  Fixed some typos and formatting issues.

test is implemented as a python script in test/python_modules/sequence/

test compares the calculation sequence to the calculation graph.

The test is run during compilation after parsing but before building.  By default, a failure will kill compilation, but
if IGNORE_SEQUENCE_ERRORS=1 in the environment, only a warning will be issued and compilation will continue.

Two out-of-order bugs are fixed.

1. Ordering simply counts how many inputs of a part of visited. When that number matches the total inputs for the part, the part is visited,
but inside a subystem, delays were counted twice.  Once on the initial pass looking for signal sources, and again as a normal part.

Parts that took input directly from delays could appear early in the sequence.

This change skips following links form delays as a normal part.

2. If a data source, including subsystem inputs, constants, delays, grounds were connected directly to a subsystem output, then
parts immediately connected from the output would be added to the subsystem sequence, though they were at a higher level.

This bug could cause these parts to be sequenced out of order.

Change is to check whether a part leading form a data source is in the subsystem.  This check is already included when following from normal (non-input) parts.

names of supported IO cards for use by print message tasks, such as print_io_info().

card_count array and check card count by type. All old card type
count variables,e.g. adc16Count, adc18Count, etc., removed from
CDS_HARDWARE structure.

 * simple process management when a test needs multiple processes
 * temp directory management (and cleanup)
 * scriptable
 * less verbose than bash

- Fix pathes for duotone test code.
- Add alarm  limits to EPICS for timing checks.

From the user perspective, key changes are in the model Parameter block settings:
- An IOP model should now be designaeted with iop_model=1
	- Previously set by adcMaster=1
- A user control application should have the adcSlave=1 parameter removed.
	- If iop_model=1 is not in the Parameter block, then RCG assumes
	  this is a user control application model.
- IOP models that send/rcv timing over the Dolphin network
	- The transmitter model Parameter block needs dolphin_time_xmit=1
	- A recevier IOP model Parameter block needs dolphin_time_rcvr=1

Builds test models (x1iop and x1tst)