Build fixes for building scigraph. Tested with sbcl/cmucl.
Consisting mostly of:
* Replacing (ignore x) with (declare (ignore x)). * Hide custom declarations in defmethod from sbcl/cmu that both choke on these. * Change defconstant on cons into a defvar, for recompilation sake. * Unwrap defpackage from eval-when. * Change the memoize macro to use load-time-value to generate a hash-table.