* add gas limit/price constants
* add gas limit/price validators & selectors
* apply new gas limit/price validation to components and sagas
* create/apply function to sanitize advanced fields input
* add types, update tests
* fix unrelated failing test
* Initial crack at simple only gas slider component.
* Work on advanced component. Refactor redux and components to specify gas limit vs price.
* Convert fee summary to a render cbesque thing.
* Rework responsive columns.
* Remove force offline button.
* Tweak styles.
* Fix tscheck issues, remove unneeded prop.
* Fix references to GasField
* Gas slider in lite send.
* Make gas slider network-aware for symbol and price calculation.
Danny Skubak
James Prado
William O'Beirne