JERSEY-2029: Document option "turn off META-INF/services lookup"
 New docs section "Turn off classpath scanning".
 Removed some duplicates in jersey.ent.

Change-Id: Idc764e2271b12a6587ba4c13113242c86573e2e5
Merge "JERSEY-2029: Document option "turn off META-INF/services lookup"  New docs section "Turn off classpath scanning".  Removed some duplicates in jersey.ent."