Log formatter should not combine lines starting "[\s*\S+\s*]"

[jsiirola]

Fixes: #N/A

Summary/Motivation:

This prevents the log formatter from combining lines that begin with "\[s*\S+\s*\]", so that log messages like the following are not reformatted:

INFO: The following extensions were downloaded:
        [FAIL]  gsl
        [ OK ]  mcpp

Changes proposed in this PR:

• Treat lines beginning with "\[\s*[A-Za-z0-9]+\s*\]" as if they were bulleted lists.

Legal Acknowledgement

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1. I agree my contributions are submitted under the BSD license.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[coveralls]

Coverage increased (+0.004%) to 61.923% when pulling ac33f23 on log-formatting into c0b323e on master.

[codecov-commenter]

Codecov Report

Merging #102 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #102   +/-   ##
=======================================
  Coverage   63.96%   63.96%           
=======================================
  Files          87       87           
  Lines        8933     8934    +1     
=======================================
+ Hits         5714     5715    +1     
  Misses       3219     3219           

Impacted Files	Coverage Δ
pyutilib/misc/log_config.py	97.36% <100.00%> (+0.03%)	⬆️

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