cleanup
cleanup
WIP
removed unwanted file
removed intermediate arrays
using &procs as argument for each
use lazy versions of Enumerator-methods

Instead of building custom Enumerators, use the lazy versions of the
built-in ones. Also, use method-objects all the way instead of one-line
code blocks or Procs.
cleanup and better logging
testing
added basic xslt converter
new source ref. regex
xml to html (XSLT, CSS)
convenience method #to_xml_u8
WIP: recognition of citations (sources)
WIP
incl. non italic sup. in cit-source when at end

<i>Meyer</i><sup>8</sup> -> <i>Meyer<no_i><sup>8</sup></no_i></i>
include degree char in italics
WIP
optional XML-strict validate changes
optional validation for TUSTEP