More cleaning up construction of arrays of things.
Introduce a utility function called, `split_on_space`
that tokenizes a string on a space character; use
it in most places where `strtok()` had been called.
More use of the ptr_vector type. Introduce a utility
function to get access to the pointers without consuming
the vector; this is used in the files code.
Signed-off-by: Dan Cross <patchdev@fat-dragon.org>
