Fix NPE in case when o.a.d.a.l.extras.codec is started before o.a.d.a.l.code.core and no LdapApiService is yet registered. Use ServiceTracker to decouple bundle start from service lookup and codec registration.

git-svn-id: https://svn.apache.org/repos/asf/directory/shared/trunk@1645870 13f79535-47bb-0310-9956-ffa450edef68
Explicit import javax packages, not all OSGi runtimes (Felix) import them by default

git-svn-id: https://svn.apache.org/repos/asf/directory/shared/trunk@1645873 13f79535-47bb-0310-9956-ffa450edef68