Used hooks to capture $stdout/$stderr during eval

This allows one to capture output only when code is being
evaluated. It also prevents a client from stealing messages from another
one if there are multiple ones.
`@client.wait` is now in `Server#run`.

This allows you to create a new instance of `Server` without blocking.
Merge remote-tracking branch 'origin/fix/multiple-connections'
Wrapped completion proc in an actual proc object (see #49)

DRbObject does not seem to implement #respond_to_missing?.
Merge branch 'fix/multiple-connections'
Merge branch 'work-around/drb-method-missing'
Added support for remote editor (closes #6)