Replace nopt with dashdash

- Use dashdash for arg parsing
- Add bin/ldapjs-* to jsl/jsstyle checks
- Fix code style issues

Fix mcavage/node-ldapjs#201
Alter usage message style

Use sections and env hints per trentm's suggestion.
Update changelog
Alter presence testing for Attribute vals

Ignoring a null 'vals' options while constructing a new Attribute object
will more closely mimic the behavior prior to mcavage/node-ldapjs#178.
Major overhaul of client connection logic

- Remove PooledClient
- Add reconnect functionality to client
- Add 'idle' client event and options