Powerline naked theme refactor

- Split functions and options in two files
- Import common functions from powerline theme
- Add README.md

themes/powerline-naked/powerline-naked.base.bash

@@ -0,0 +1,15 @@
+. "$BASH_IT/themes/powerline/powerline.base.bash"
+
+function __powerline_left_segment {
+  local OLD_IFS="${IFS}"; IFS="|"
+  local params=( $1 )
+  IFS="${OLD_IFS}"
+  local separator_char=""
+  local separator=""
+
+  if [[ "${SEGMENTS_AT_LEFT}" -gt 0 ]]; then
+    separator="${separator_char}"
+  fi
+  LEFT_PROMPT+="${separator}$(set_color ${params[1]} -) ${params[0]} ${normal}"
+  (( SEGMENTS_AT_LEFT += 1 ))
+}