* btree.lisp: New file providing binary tree search for
sorted vectors
* tests.list: Add tests for binary tree search
* mop.lisp: Change pushed cl:*features* to be in KMRCL
package, not KEYWORD
* attrib-class.lisp: Use new mop *feature* names for reader
conditionals
* io.lisp: Add def-unsigned-int-io, along with function
definitions for binary io of 2 through 8 byte unsigned ints.