Make _build_uri_path output predictable

This is done by ensuring that filters are
serialized in their alphabetical order.

Tweak tests affected by this.

This is done in the context as defined by
etherpad: neutron-random-hashseed

Partial-bug: #1348818

Change-Id: Ibe79716a340195ca0365f276ef6e3e728f1a94a1
Fix 500 error  during router-update for dvr routers

This was caused because the l3 service plugin was
erroneously calling a method on self, whereas the
method is implemented by the core plugin.

Closes-bug: #1352786

Change-Id: I0746eee314730370b2df4bef6d9fd41680e2e3d1
Merge "Make _build_uri_path output predictable"
Merge "Fix 500 error  during router-update for dvr routers"