Finish RubyServ::Database

This implements the ability to use a json flatfile database system.

A database can be created or loaded by doing:

RubyServ::Database.use('database_name')

This will create a database if it does not exist in data/database.json
with a empty json hash, then read it.

Example of complete usage:

db = RubyServ::Database.use('test')
db[:name] = 'james'
db.save    # Saves the set data to data/test.json
db[:name]  # => 'james'
db.destroy # Deletes the data/test.json file