Switching from MabXml to the new AlephMaxRecord DocumentType
Version bump
Structure the AlephMabRecord class
New DataField structure for better querying
Add test suite for AlephMabRecord data structure
Remove uncommented code
Tests for query of multiple fields with different subfields
Support for multiple instances of the same SubField in a DataField
Mabmapper-merge: Write fields if they equal to false
Version bump
No exit on error in permissive mode
Various changes of the DSL
Fix: Filter datafields were subfields don't exist
Fix: Don't ignore fields with value false
Add method Subfield::Set#has_subfield? with alias include?
Add ActiveSupports Object extension manually

Since they are not supported for Delegators.
Mabmapper-port: Updated dependencies (mostly stringex)

 https://github.com/ubpb/mabmapper/commit/88143ea2b621b6d9af6295ac85ca7d0199e6de50

also add rake as a development dependency to allow 'bundle exec rake'
Merge branch 'mab-document'