make thing more modular

*mathworld.t
*prototyping of filter function

*Mathworld.pm
*get rid of some nasty shit
* adding foundation.t
this test will be cover one complete walk through the tree
it is hard copy paste code inside, will be improved next time
* Mathworld.pm
integrate myfilter sub from test
exporting %ignore hash
*mathworld.t
just little adjustments