added null guards
Merge pull request #535 from adamralph/null-guards

added null guards
fix for #538 added logic to ignore assembly load failures in the MEF catalogs and log them
#538 Changing logic to display a single warning if a load failure occurs
Adding unit test for assembly load failures
Adding more tests
Merge pull request #539 from glennblock/538

Fix for #538 to ignore assembly load failures and treat them as warnings.
no args with loglevel should send you into REPL
added tests and check against the default Log value (Info) instead of hardcoded strings
passing a default loglevel info should not drop you into help but into REPL too
Merge pull request #541 from filipw/540

drop user into REPL if only loglevel is provided
Update LICENSE.md

updated year
Update README.md