Implement transaction builder

[connor4312]

This lets us do things such as distributed locks, like so:

function lock() {
  return client.if('my_lock', 'createdAt', '==', 0)
    .then(client.put('my_lock').value(id))
    .else(client.get('my_lock'))
    .commit()
    .then(result => console.log(result.succeeded === id ? 'lock acquired' : 'already locked'));
}

function unlock() {
  return client.if('my_lock', 'value', '==', 0)
    .then(client.delete().key('my_lock'))
    .commit();
}

[SimonSchick]

rm?

[SimonSchick]

Or make that @example

[connor4312]

yea....

[connor4312]

Typedoc in general is disappointing, but there's no way I'm going to manually typedef all those RPC interfaces for esdoc.