TASKS: More thoughts on ASTs
simtest: Use full call sequence in anonymous variable names

Previously this left off the current call.  This call sequence
information in anonymous variable names is only used for debugging, so
this doesn't affect correctness.
tools: Fix bug with asymmetric call sets

Previously, TestSet only gathered up the first call in all callsets.
For callsets that include all self-pairs (including complete callsets)
this is okay, but for hand-specified ones it can easily omit calls.
viewer: Put most of mkdb in a module
viewer: Self-contained command to serve and start viewer

This makes it easy and convenient to interactively explore mscan
results.
viewer: Focus on new 'view' command in README