viewprof
========
Usage: viewprof.lisp PROG.prof
Keys:
j - move one line down
k - move one line up
Ctrl-d - move down half a page
Ctrl-u - move up half a page
space - fold/unfold a subtree
h - scroll to the left
l - scroll to the right
r - enter/leave `bottom-up mode'
q - exit the program
In `bottom-up mode' the parent-child relationship of the tree structure will be reversed,
which means a function becomes a parent of its caller.