- Add support for the new "phonetic" relation modifier,

	- Add support for the new "phonetic" relation modifier,
	  including its mapping in "etc/pqf.properties".
	- Make prefix-maps bind loosely, so that ``>dc=x a and b''
	  applies the dc=x binding to both the ``a'' and ``b''
	  sub-queries.
	- Write javadoc comments for CQLRelation and ModifierSet.
	- Other improvements to javadoc comments (e.g. describe the
	  `config' parameter to the toPQF() method.)