Separated elastic:drop and :map rake tasks

Elasticsearch rake tasks needed a little more clarity. Drop, map and
import separated into respective tasks.
Removed account listing on guest dashboard

We no longer want the guest dashboard to show the accounts on the
system.
Limit account slug length within 3 to 12 characters

Only accept 3 to 12 characters in account slug.
Tweaked delete button on account#edit
Gemfile: Update gems, added separate jquery-ui-rails

New version of jquery-rails no longer includes jquery-ui. Added
jquery-uin-rails gem. Also released version lock on multi_json. New
version no longer throws spurious error messages.
Added gem devise_invitable

All users must be invited to join by the account owner. DeviseInvitable
adds invitation framework to user authentication gem Devise.
Invite user from account creation

Initial user is invited/created from accounts#new. It's simple right
now, creating the account and inviting the user. Needs membership
management in account to add user as "owner" of the account.
Increase account slug limit to 24 characters

Some account owners might want longer subdomains so the limit was
increased to 24 characters. The minimum is still three characters.
Member model embedded in accounts to track user roles

Users roles of owner, active, inactive saved in member model embedded in
account record. Member.user belongs_to user so user_id stored in member
model. Member role defaults to 'active'.
Fixed embedded_in plurality error for contact embeds

EmbeddedIn contact declarations for address, phone and email models
incorrectly specified "contacts" instead of "contact".
User's fullname included in invitation and acceptance

Admin can add user's name and email for inviting to use system. User can
change invited name on acceptance.
Expanded account#show

Add uneditable list of members to account#show. Move account_edit link
to account#show.
Note: Account deletion does not remove account data

Resolve #24: For now simply remove account without removing account
data.