Attempt aligning bash with zsh

- support PROMPT
- support RPROMPT (buggy if on same line)
- support zsh color codes in PROMPT and RPROMPT
- refactor set_prompt to use PROMPT and RPROMPT
- add duration and rc to RPROMPT

bash/rc

@@ -19,14 +19,28 @@ GIT_PS1_SHOWSTASHSTATE=1
 GIT_PS1_SHOWUNTRACKEDFILES=1
 
 precmd() {
-    LAST_CMD_RC=$?
+    CMD_RC=$?
+
+    if [[ -n ${CMD_START} ]]; then
+        CMD_END="${EPOCHREALTIME}"
+        CMD_DURATION=$(bc <<<"${CMD_END} - ${CMD_START}")
+        unset CMD_START
+        unset CMD_END
+    fi
+
     _direnv_hook
     #clear_incomplete_line
     set_prompt
+    apply_prompt_rprompt
     update_terminal_cwd
     set_term_title
 }
 
+preexec() {
+    set_term_title
+    CMD_START="${EPOCHREALTIME}"
+}
+
 chpwd() {
     __git_ps1_gitdir
     _gopath