* Filter out the evm denom from min gas prices in the cosmos-sdk ante
chain; this allows '0ukava;1000000000akava' to be used in order to
still support zero fees for cosmos based transactions
* support called context in mock
* ensure min gas prices is always a valid (and sorted) DecCoins
* add doc comments
* use kava antehandler
* add authenticated mempool decorator
* add get authorised address methods
* hook antehandler into app
* refactor address fetcher interface
* tidy up args to NewApp
* remove unused function
* tidy up after removing address fetcher interface
* read authorized addresses from config
* fix error message, and minor tidy
* update cosmos-sdk and tendermint
* clarify function name
* add flags for mempool options
