* Quoted ")" in function
* Possible to specify if unknown variables is non-zero, real, positive
* (x+y)/z should return (x+y)/z instead of x/z + y/z
* Infinity
* Limit fraction precision
* Do not recalculate plot data when it has not changed
* Instant apply for all parameters in plot
* Plot-functions
* Check if unit is used on delete
* Replace pointers to unit when unit type has changed (a different object must be created)
* Export to CSV file
* Sort out percentile and provide alternative methods
* Ask for exchange rate update on demand
* Improve matrix editing
* Sort out cases where we should not do anything because x is unknown, 
  such as sqrt(-5x) which now returns sqrt(-5) * sqrt(x)
* Conditional if (y / x) * x = y if x != 0
* Get rid of wget dependency
* Split up interface code
* Move unknown over to the other side in unsolved comparison
* Sort out x^-y -- (1/3)/(x+y)=1/3(x+y) but 1/3(x+y)=1/(3x+3y)

* More functions
* More units

* Separate library
* Increase support for non-glibc systems

* API documentation

* Better graphs/charts (do not use gnuplot)
* Script/code plugins for advanced functions
* Command line version
* Gnome/KDE applets
* QT version
