Reduce graph perf

[timbitz]

This pull request fixes a few performance bugs:

• Set a max-iteration number in case of runaway reduce-graphs iterations
• Set a minimum percent weight threshold to filter "cryptic skipping reads" at high depth
• Create a new memory friendly reduce_graph for constitutive inclusion or exclusion
• Tag v0.8

[timbitz]

Codecov Report

:exclamation: No coverage uploaded for pull request base (master@daee844). Click here to learn what that means. The diff coverage is 45.45%.

@@            Coverage Diff            @@
##             master      #48   +/-   ##
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  Coverage          ?   46.43%           
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  Files             ?       16           
  Lines             ?     1951           
  Branches          ?        0           
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  Hits              ?      906           
  Misses            ?     1045           
  Partials          ?        0

Impacted Files	Coverage Δ
src/events.jl	56.29% <45.45%> (ø)

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