tried to get single cancellation working.
single cancellation addition, take 2
bunch of updates for monitoring (single versus double issues)
distinguished between ConjointChecks and ConjointChecks_exp functions. The latter is meant to experiment with the limits (not for production).
Added SingleCancel functionality to check row or column cancellation.
added option to collapse columns to PrepareChecks
added option to check based only on the double cancellation restrictions.
added .Rbuildignore to get rid of README.md