Authorization roles to access account members

Limit access to account members to the account owner only. Implements
CanCan for authorizing actions.
Renamed account members: associates

Members sound like external customers. Users are individuals on the
system, but they can sometimes access more than one account. Account
associates seems more clear.
Updated devise to zurb foundation

Devise forms used twitter bootstrap. Switched to zurb foundation.
Owner can invite new associates

New associate invitation. Simple for now. Full name is optional.
Currently no mechanism to reuse existing User, yet.
Cleanup specs and consolidate account spec setup

Removed fixtures which don't use. Consolidated account setup into
shared_specs. General cleanup.
Added account method to ScopeAccount module

When including Roundtablecrm::ScopeAccount a method is added to
enumerate the account. It's a simple call to Account.find with stored
account_id.
Scope user for contacts, memos, import_contacts

Roundtablecrm::ScopeUser module set up with basic testing. Added module
to contact, memo, import_contact models. Also changed authentication to
subdomain controller which also populates Account.current_id and
User.current_id.
Cache user.name in memo

We are caching user.name, person.name and company.name in memo to save
state at the moment the memo is created. It also enhances performance as
all data necessary for memo display is stored in the memo itself.
Minor improvements to note partial

Added user, long date, person and company names to note rendering. It's
still rough but good enough to start with.
Import rake task assigns user_id

When running the import:contacts rake task, we have to assign the
user_id of the original import_contact record so all imported records
have a valid user.
Moved note delete to note edit

To help stop accidental note deletion we moved the DELETE NOTE button to
the note edit screen.