Add basic server API tests
Refactor server route handling

Force route lookups to proceed lexically through mounted endpoint DNs.
Mounting to a null ('') DN will act as the default route for requests
which aren't matched by defined routes.

Fix mcavage/node-ldapjs#154
Fix mcavage/node-ldapjs#111
Merge pull request #195 from pfmooney/route-pr

Server request routing update