Add :redefd-vars lint check
First version that seems to work with tools.analyzer contrib library

rather than the analyzer library or jvm.tools.analyzer.

Still needs a lot of work, since only the new :redefd-vars linter
works.  At least, it is the only one I have tested since moving to
tools.analyzer.
Comment out some debug print messages
Update :def-in-def linter check for now tools.analyzer ast format
Trim default-linters down to those that have been updated to tools.analyzer
Update README with a list of known bugs
Detect defonce and defmulti macroexpansions to avoid giving :redefd-vars warning for them
Make repeated defmulti or defonce definitions of a var flag a warning

Before this change, defmulti and defonce macroexpansions were not
remembered as any def at all, not even one.
Add some TBD questions about how macroexpand is behaving
Missing 'and' in a function.
Search for files in Leiningen :test-paths in addition to :source-paths
Change default behavior of option :eval to :all
Change debug options to a set of keywords on :debug key
Answer some questions I left to myself in comments
Update :misplaced-docstrings linter for use with tools.analyzer
Typo
Add test cases for some lint warnings
Add many test cases.
Update README