Major syntax changes

[jsn1993]

This PR implements four important syntax changes:

• __call__ connection is deprecated. This is somewhat convenient but the keyword argument approach doesn't work for cases when we need to connect individual ports in the interface.
• Signal now only takes Bits or bitstruct type. We used to allow arbitrary type but throughout the practice we don't find creating Wire(int) very useful.
• Signal now allows taking a single integer N as a shortcut for mk_bits(N). This might avoid a lot of mk_bits calls ...
• Support @update and @update_ff. Dropping @s.update.

[codecov[bot]]

Codecov Report

Merging #155 into dev-1.0-release will increase coverage by 0.13%. The diff coverage is n/a.

@@                 Coverage Diff                 @@
##           dev-1.0-release     #155      +/-   ##
===================================================
+ Coverage            89.26%   89.40%   +0.13%     
===================================================
  Files                  283      284       +1     
  Lines                24248    24232      -16     
===================================================
+ Hits                 21645    21664      +19     
+ Misses                2603     2568      -35     

Impacted Files	Coverage Δ
...translation/behavioral/SVBehavioralTranslatorL3.py	75.86% <0.00%> (-13.80%)	:arrow_down:
pymtl3/stdlib/ifcs/GetGiveIfc.py	51.64% <0.00%> (-14.29%)	:arrow_down:
...nslation/behavioral/YosysBehavioralTranslatorL3.py	44.44% <0.00%> (-3.71%)	:arrow_down:
pymtl3/datatypes/PythonBits.py	84.78% <0.00%> (-0.73%)	:arrow_down:
pymtl3/passes/sim/DynamicSchedulePass.py	96.47% <0.00%> (-0.59%)	:arrow_down:
pymtl3/dsl/ComponentLevel2.py	97.69% <0.00%> (-0.33%)	:arrow_down:
pymtl3/dsl/Connectable.py	82.77% <0.00%> (-0.24%)	:arrow_down:
pymtl3/stdlib/cl/StallCL.py	100.00% <0.00%> (ø)
pymtl3/passes/tracing/CLLineTracePass.py	97.97% <0.00%> (+2.02%)	:arrow_up:
pymtl3/passes/sim/AddSimUtilFuncsPass.py	90.32% <0.00%> (+9.67%)	:arrow_up:
... and 1 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 17854d4...08fdd2a. Read the comment docs.