A new page has been created for viewing assets. This replaces the old
`selectedToken` state, which previously would augment the home page
to show token-specific information.
The new asset page shows the standard token overview as seen previously
on the home page, plus a history filtered to show just transactions
relevant to that token.
The actions that were available in the old token list menu have been
moved to a "Token Options" menu that mirrors the "Account Options"
menu.
The `selectedTokenAddress` state has been removed, as it is no longer
being used for anything.
`getMetaMetricState` has been renamed to `getBackgroundMetaMetricState`
because its sole purpose is extracting data from the background state
to send metrics from the background. It's not really a selector, but
it was convenient for it to use the same selectors the UI uses to
extract background data, so I left it there for now.
A new Redux store has been added to track state related to browser history.
The most recent "overview" page (i.e. the home page or the asset page) is
currently being tracked, so that actions taken from the asset page can return
the user back to the asset page when the action has finished.
* Add `react/no-unused-prop-types` rule
All detected unused prop types have been removed. I have attempted to
ensure these props are no longer passed in either.
* Update handling of props to avoid false positive lint errors
These cases were detected by `react/no-unused-prop-types` as being
unused props, even though they were used. These minor adjustments
prevent them from being flagged as errors.
* Update unit tests
Many of these tests were just checking that specific props were passed
from containers or to a child component. These were deleted, as I can't
imagine how they'd be useful.
* Disable `react/no-unused-prop-types` in `componentWillReceiveProps
The rule `react/no-unused-prop-types` doesn't seem to be detecting
props used within `UNSAFE_componentWillReceiveProps`. The two cases
have been disabled temporarily until we can replace these unsafe
lifecycle functions.
