Following on from the previous commit, use of `RPS1` results in the
prompt being redrawn when the terminal gets narrower, this makes the
line drawn by `fresh_line_one` scroll off the screen. By removing any
use of `RPS1` this behaviour goes away.
* When a command fails, don't print the error code at the end of the
first line but directly after the git stats.
* Remove `cr` from `prompt_opts` since there is no longer a new line in
`PS1`, combined with above, this result in no new lines being inserted
when the terminal becomes narrower e.g. a horizontal tmux split.
* Remove `fresh_visible_length` function and instead use the length of
string variables e.g. `${#userhost}`.
* Add option parsing to `prompt_fresh_setup` to detect when options are
set during setup.
* Add `-a` option to enable almostontop behaviour, every time a command
is invoked the screen is cleared and the is prompt redrawn before the
command begins using the `preexec` hook. `-a` is disabled by default.
* Add `prompt_fresh_help` function to display a description of available
options using `prompt -h fresh`.
* Canonicalize all utility functions for the fresh prompt theme to
follow the `fresh_<name>` convention.
Fixes#1.
