Add the parameter be_clever to both functions.  When be_clever is FALSE,
smart home and dynamic home are disabled in do_home(), and dynamic end is
disabled in do_end(), so that these functions only move to the beginning
or end of the current line or chunk.

This simple home and end functionality is needed to improve do_left()
and do_right()'s horizontal behavior with softwrapped chunks, which is
forthcoming.