Add XML output of Forms

[LFDM]

Make it compliant to the standards used by @balmas' morphology service.
We need and want to compare different morphology units to be comparable against each other.

[LFDM]

The Schema itself:
https://svn.code.sf.net/p/alpheios/code/xml_ctl_files/schemas/trunk/lexicon.xsd

Example output from morphology service - something like this should be our target:
http://services.perseids.org/bsp/morphologyservice/analysis/word?word=corpusculum&lang=lat&engine=morpheuslat