2011-08-12: release 0.9.2
  [+ui] Added two predefined macros STRINGIFY and CONCAT for making
        string literals and for building identifiers respectively.

2011-07-20: release 0.9.1
  [+ui] Added support for processing sections of files using external programs
        (#ext/#endext, -x option)
  [doc] Moved and extended documentation into the README file.

2009-11-17: initial version 0.9.0
