Remove dir_bookmark.sh script from Bash
Bash: improve hman output formatting
Bash: hman will now just execute `help` for builtin commands.
bash: change .bash_profile to use $PATH directly, not $MYPATH.

This saves us polluting a global environmental variable.
bash: add shell nesting level indicator to $PS1
bash: add hack s.t. $PS2 is indented the same as $PS1
tiny change: add newline to end of .homesick_subdir file