Merge PR #3656: Broken-Invar Tx - aka. Crisis module

* beginning thinking on issue

* ...

* working

* working

* working fee pool distribution

* spek outline

* spec update

* gas refund calculations

* simulation saved to ~/.gaiad/simulations/

* lean simulation output

int

* cleanup bank simulation messages

* operation messges

int

* lint

* move simulation to its own module

* move simulation log code to log.go

* logger overhaul

int

* distribution comments

* fix compiling

* cleanup modifications to x/distribution/keeper/allocation.go

int

int

int

* gov bug

* result.IsOK() minimization

* importExport typo bug

* pending

* address @alexanderbez comments

* simple @cwgoes comments addressed

* event logging unified approach

* distr module name constant

* implementing

* compiles

* gaia integration

* proper constant fee removal

* crisis genesis

* go.sum update

* ...

* debugging

* fix sum errors

* missing err checks

* working implementing CLI

* remove query command

* crisis expected keepers in other modules

* crisis testing infrastructure

* working

* tests complete

* modify handler to still panic if not enough pool coins, docs working

* spec tags

* docs complete

* CL

* assert invariants on a blockly basis gaiad functionality

* gaiad CL

* transaction details in runtime invariance panic

* Apply suggestions from code review

Co-Authored-By: rigelrozanski <rigel.rozanski@gmail.com>

* sender tags

* @mossid suggestions

int

* @cwgoes comments final

* Apply suggestions from code review

Co-Authored-By: rigelrozanski <rigel.rozanski@gmail.com>

* bug seems fixed (#3998)

* delete unused line in zero height export bug

x/auth/stdtx.go

@@ -150,6 +150,15 @@ func (fee StdFee) Bytes() []byte {
 	return bz
 }
 
+// GasPrices returns the gas prices for a StdFee.
+//
+// NOTE: The gas prices returned are not the true gas prices that were
+// originally part of the submitted transaction because the fee is computed
+// as fee = ceil(gasWanted * gasPrices).
+func (fee StdFee) GasPrices() sdk.DecCoins {
+	return sdk.NewDecCoins(fee.Amount).QuoDec(sdk.NewDec(int64(fee.Gas)))
+}
+
 //__________________________________________________________
 
 // StdSignDoc is replay-prevention structure.