Fixes and Section/Property tests

[mpsonntag]

This PR fixes various issues and pushes Section and Property tests.

• When a Property is cloned, the parent of the clone is now properly set to None.
• When a Section or a Property is cloned, a new id is set for the clone and of any cloned children. Also see Assign new UUIDs to clones by default, add keep_id flag #259.
• Excludes id when comparing an odML entity for equality. Closes Exclude id in the baseobject.__eq__() method #260.
• Avoids an AttributeError on get_path() when a Property has no parent. Closes [Property] AttributeError when calling get_path() with unset parent #256.
• Avoids an AttributeError on get_merged_equivalent when a Property has no parent. Closes [Property] AttributeError when calling get_merged_equivalent() with unset parent #257.
• The unused and outdated (v1) test xml file test_odMLMetadata.xml was removed.
• test_section: updates test_id() and adds test_clone()
• test_property: updates test_id() and adds test_get_path(), test_get_merged_equivalent() and test_clone().
• test_property_integration: Adds the file to test saving and loading of Properties with all different parsers.

[coveralls]

Coverage increased (+0.2%) to 71.673% when pulling 7410cc0 on mpsonntag:propertyTest into 7041e7f on G-Node:master.