* simplify mock tx type, msgs, and handlers
* remove dependencies on auth and bank
* dedup with setupBaseApp
* lots of comments and cleanup
* fixes where we weren't checking results
* use some table driven tests
* remove TestValidatorChange - its not testing anything since baseapp
doesnt track validator changes
* prepare for CheckTx only running the AnteHandler
* fix runTx gas handling and add more tests
* new tests for multi-msgs