Merge PR #2365: Validator Commission Model

* Update validator commission fields

* Remove CommissionChangeToday and update to use CommissionChangeTime

* Implement commission as a first class citizen type

* Implement stringer for Comission

* Move commission type and logic to new  file

* Add new commission errors

* Add commission to create validator message

* Implement and call UpdateValidatorCommission

* Update godoc for UpdateValidatorCommission

* Add Abs to the decimal type

* Implement new SetValidatorCommission

* Update decimal short godocs

* Move set initial commission logic

* Move initial commission validation to Commission type

* Update initial validator commission logic and unit tests

* Remove commission update time from struct and move to validator

* Update validator create handler tests

* Implement commission logic for CLI

* Fix make lint failure

* Fix make cover failure

* Update edit validator logic to handle new commission rate

* Fix lint and cover

* Update create/edit validator simulation to include commission params

* Update MsgEditValidator godoc

* Update pending log

* Update staking tx docs

* Fix CLI create validator test

* Update variables names for commission  strings

* Merge UpdateTime into Commission type

* Update create-validator usage in docs

* Update more docs with examples

* More doc updates

cmd/gaia/cli_test/cli_test.go

@@ -238,6 +238,9 @@ func TestGaiaCLICreateValidator(t *testing.T) {
 	cvStr += fmt.Sprintf(" --pubkey=%s", barCeshPubKey)
 	cvStr += fmt.Sprintf(" --amount=%v", "2steak")
 	cvStr += fmt.Sprintf(" --moniker=%v", "bar-vally")
+	cvStr += fmt.Sprintf(" --commission-rate=%v", "0.05")
+	cvStr += fmt.Sprintf(" --commission-max-rate=%v", "0.20")
+	cvStr += fmt.Sprintf(" --commission-max-change-rate=%v", "0.10")
 
 	initialPool.BondedTokens = initialPool.BondedTokens.Add(sdk.NewDec(1))