webadmin: Houskeeping in Provider main tab and popup

Closed possible loopholes, removed redundant code, changed method
access modifiers, added constants to represent command names,
formatted code for uniformity within files.

Change-Id: Ie5d4225174e733588010a46325674df2165c8814
Signed-off-by: Lior Vernia <lvernia@redhat.com>