Merge transactions into memo

Using separate memo subclass for transactions is proving to be a
liability. We need the ability to add transaction information directly
to memos.
Transaction fields added to note form
Migrate transactions task

The migrate:transactions task will rename transactions to notes. Destroy
all user boxes. Rebuild memo index.
Note field $ button unhides transaction fields

The transaction fields are hidden by default. This enables the $ button
to unhide those fields. For prexisting notes that have transaction
information already, the fields are left unhidden.
Gemfile: Added unf, removed thin

Updated gemfile. Added unf to stop fog from complaining. Removed thin
webserver. Use webrick instead.
Added transaction fields on contact note form

When on a contact we want to disable the transaction button and hide the
transaction fields for the note form. When a related project is selected
the transaction button is enabled. If clicked, it slides down the
transaction fields. If the project is removed, the transaction fields
are hidden and the transaction button is disabled.
Merge transactions into memo class