Fixed #990 Deleted references to geolocation, maps, guessing location

Closes https://openhatch.org/bugs/issue990.

Deleted code in the settings page that has any mention of geolocation and maps,
including geo-location-related html, views, and tests.

Changed default url link "settings" on header from
/settings/location/ to /settings/invite_someone.

Made design decision to re-structure left-hand navigation bar on
settings page in order to improve UI:
    "Tell friend about OpenHatch" tab appears first on top left,
    followed by the "Widgetize yourself" tab, and finally,
    the "Email", "Name", and "Password" navigation tabs.