Aldor: Don't try to evaluate conditions on categories where the category
is already unconditionally part of a category's parents.

git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1664 b0c55286-4f34-0410-a049-a1e7e93b0762
Aldor: Use newer hash function.

Note that this change makes older versions of aldor incompatible with this
code.

git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1665 b0c55286-4f34-0410-a049-a1e7e93b0762