LIVEOAK-608, LIVEOAK-609: Fix several issues with app clients

LIVEOAK-608: Fix validation (was validation previous input), when name
is empty, and when editing back to original name;
LIVEOAK-609: Updated the update call to use client id instead of name;
Merge pull request #368 from ammendonca/LIVEOAK-608-609

LIVEOAK-608, LIVEOAK-609: Fix several issues with app clients