adding mime check for text datastream indexing
Merge pull request #60 from willtp87/modular

adding mime check for text datastream indexing
Merge pull request #62 from adam-vessey/modular

Rewrite RELS-EXT to be more templatey and create fields copies with more specific names.
Inline the PID placeholder and alternative replacement.

Also, add in "hierarchy.xslt" template and commented-out invocation.