pxmake 0.18.0

New features

• px_data() has a new argument, labels, which makes the function return the
  data table with VALUES instead of CODES. (#419)

Breaking changes

• ELIMINATION is changed from language dependent to not language dependent, and
  instead of adding ELIMINATION as values, it is done with codes. (#406)

Bug fixes and minor improvements

• Bugfix when saving as R scripts. (#410)
• Elimination values and order are preserved when changing data table. (#418, #420)