Reinstated the POM's m2e plugin config
Add a 'with_nodes' profile

As stated in the README.md, this allows for the build of the nodes server
to be optional. Specifying the profile, the build is unchanged.

Should fixes the issue #425
Merge pull request #426 from tledoux/node-profile

Add a 'with_nodes' profile
Merge pull request #423 from IDPF/feature/pub-types

Support custom schema-based checks for specific publication types
Merge pull request #424 from IDPF/feature/pom-m2e-config

Reinstated the POM's m2e plugin config
Add support for RDFa attributes.
Add support for defaultAction, phase and propagate on epub:trigger
Add support for Microdata attributes
Add support for custom ns attributes in xhtml content docs
Add support for aria-describedat in XHTML, add support for epub:type on
SVG.
Add new set of recognized epub:type values (301)
Additional microdata tweaks
Disable a test verbosity flag
Merge pull request #428 from IDPF/301-update/contentdocs

Updates to Content Doc checks for EPUB 3.0.1
Report the missing manifest reference for a page-map seperatly so it can have a different severity from other missing manifest errors
Merge pull request #429 from IDPF/p/apond/cr/opf_063

Report the missing manifest reference for a page-map separatly so it can...
Fix dc:type and dc:source rules for EPUB 3.0.1

The restriction to only one of these elements has been removed.
Added one test case for each element.
Simplify tests with a @Before setup  method
Add support for the 'source-of' OPF metadata

  * added it to the list of known properties
  * added Schematron checks for:
     * its allowed value
     * must have a `@refines`
     * the @refines target must be `dc:source`
  * added tests
Support for 'record' link elements (3.0.1)

  * link elements of type 'record' are now allowed
  * they must have a `media-type` attribute (schematron test)
  * they must not refine another property or element (schematron test)