Fixed Issue #6: Definig $PROMPT_START $PROMPT_END out of gitprompt.sh

It is now possible to override PROMPT_START and PROMPT_END by exporting the variables GIT_PROMPT_START and GIT_PROMPT_END

gitprompt.sh

@@ -51,8 +51,17 @@ function git_prompt_config()
   # local Time12a="(\@))"
   local PathShort="\w"
 
+  if [ "x${GIT_PROMPT_START}" == "x" ]; then
     PROMPT_START="${Yellow}${PathShort}${ResetColor}"
+  else
+    PROMPT_START="${GIT_PROMPT_START}"
+  fi
+
+  if [ "x${GIT_PROMPT_END}" == "x" ]; then
     PROMPT_END=" \n${White}${Time12a}${ResetColor} $ "
+  else
+    PROMPT_END="${GIT_PROMPT_END}"
+  fi
 
   EMPTY_PROMPT="${PROMPT_START}${PROMPT_END}"