Added memoization to text label generation

Should be good for performance
Forwarding axis updates

* Axis updates applied to Panel are translated all the way to the
contexts.
* Related: a Graph can now issue only one DataInterface.
* Unrelated: the tables are now allocated empty to avoid allocationg
tables too big (should precalculate the final size, actually)
* Unrelated: removed ST(). It's not necessary now that I know of
Date.now().
* Removed a console.log from newton.
Added to-do list.