added trim and to lower in domain validation
Made the signup and volunteer dialogs i18n configurable.

The checkbox for TOS and the text on the volunteer dialog are
now configrable via the i18n interface.

Implemented for 18F/midas-open-opportunities#1
Merge pull request #349 from brandtheisey/devel-email-validation

Trim and tolower in email domain validation
Switching translation variables to modified camelCase.
Merging in the home page changes
Removed 'AObject' translation entries in favor of 'ObjectIndefinite' entries.
Merge pull request #352 from DavidEBest/devel-i18nTOS

signup and volunteer dialog text should be configurable.