0.5:
  * Enum type
  * Ln type
  * Frontend asks to open of file if none given
  * Bgcolor for image and pngcairo plugin
  * Real-time
  * File output as parameter, instead of always stdout
  * When printing labels over lines, you can now use print=false
    not to print a given axis
  * Colors can be set as (n,n,n) ( 0 <= n <= 1 )
  * Port variable
0.4:
  * Heatlines
  * Relative as axis property
  * Learning mode
  * Cairo plugin
  * Height as image property
  * Multiple conditions for filtering
0.3:
  * Filters
  * Added penwidth property
  * CSV plugin
  * SDL plugin
  * PCV tool rewritten
  * Properties managed with hash
  * Reworked on linked list
  * PCRE filtering capabilities (pcv -Wpcre)
0.2:
  * UTC Type
  * PLPlot plugin
  * Multiple PCV files inclusion
0.1: Initial release
