take order into account when format month name

- avoid strange order of month and year
    if VERSION.SDK_INT >= JELLY_BEAN_MR2(18) use cc59f3b48bef6a1a831888befd429302bd10ab5f
    else use old DateUtils because I don't know how to get the right order at mCurrentLocale
- change MONTH_FORMAT to "M y"
- code cleaning