Right now any custom parameter passed on the command line is rejected (ie. all the ones not defined in pakeapp class).
It would be nice if the user could add support for custom parameters, a la java (eg. -Dmyparam=myvalue), or by plain registration of more options.
As far as I can tell, this is now impossible, as the function run() does not allow to specify extra options definitions, but only options values. Also the do_option() method should be modified accordingly