v0.13.6

• rework done on compounding in MBMA. (still work in progress)
• lots of improvement in MBMA rule handling. (but still work in progress)
  • support for 'glue' rules added.
  • support for 'hidden' morphemes added.
  • proper CELEX tags are outputted now in the XML
  • some structure labels have better names now
• removed exit() calls from library modules (issue #17)
• added languages option which is handled over to ucto too.
  • detect multiple languages
  • handle a selected language an ignore the rest