(QENG-743) Beaker options hash 'merge' should not modify the...

...global settings
- merge was behaving like merge!
- merging two OptionsHash objects should result in a new OptionsHash
  and not affect the original hashes at all.
Merge pull request #288 from anodelman/options-hash-merge

(QENG-743) Beaker options hash 'merge' should not modify the...