Added back handler getters on various servers

Signed-off-by: Julien Viet <julien@julienviet.com>
Rename Headers back to MultiMap.

Signed-off-by: nscavell <nick.scavelli@gmail.com>
Merge pull request #923 from vietj/master

Added back handler getters on various servers
Merge pull request #924 from nscavell/multimap

Rename Headers back to MultiMap.
Support metrics for Vert.x

Signed-off-by: nscavell <nick.scavelli@gmail.com>
Remove TimeUnit from metric API

Signed-off-by: nscavell <nick.scavelli@gmail.com>