unbreak temporary disabling of hidden fields in buckets.js
unbreak temporary disabling of hidden fields in buckets.js

Refactoring in cb7a2586d2dd59c7e07ccb220cba9d0fa1cb7182
"jQuery-fication of setBoolAttribute for simplicity and chaining"
quite obviously broke things by removing initialization of
nonPersistent variable. So cleanup part was never invoked after that
commit was applied.

In order to avoid issues like that in future I've renamed variable to
hopefully better name and added comments about what and why we're
doing here.

Change-Id: I6d0b2121c62f4298f56a52911953330743aa0957
Reviewed-on: http://review.couchbase.org/13211
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

mschoch/ns_server,daverigby/ns_server,mschoch/ns_server,pavel-blagodov/ns_server,membase/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,vzasade/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,ceejatec/ns_server,ceejatec/ns_server,daverigby/ns_server,membase/ns_server,membase/ns_server,pavel-blagodov/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,membase/ns_server,nimishzynga/ns_server,daverigby/ns_server,vzasade/ns_server,vzasade/ns_server,membase/ns_server,mschoch/ns_server,membase/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,nimishzynga/ns_server,ceejatec/ns_server,nimishzynga/ns_server,ceejatec/ns_server,daverigby/ns_server,pavel-blagodov/ns_server,nimishzynga/ns_server,daverigby/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,mschoch/ns_server,ceejatec/ns_server,vzasade/ns_server