Add methods to modify the receiver and avoid Marshal.dump/load.
YAML.load produces a new hash, no need to clone it.
Clone the hash once, then call in place modifier methods.
Fix reorder issue for DynamicDropDownLists when refreshed with button

All related BZs:
https://bugzilla.redhat.com/show_bug.cgi?id=1056176
https://bugzilla.redhat.com/show_bug.cgi?id=1152322
https://bugzilla.redhat.com/show_bug.cgi?id=1153833
No one calls symbolize directly so don't keep it around.

Unfortunately, MiqDbConfig calls ConfigurationEncoder.stringify, so we can't drop
that yet.
Merge pull request #889 from jrafanie/less_hashy_configuration_encoder

Don't clone so many hashes in ConfigurationEncoder
Merge pull request #900 from eclarizio/bz1056176

Fix reorder issue for DynamicDropDownLists when refreshed with button