Fix file extension on saving (fix #268)
Fix file extension on saving (fix #268)

uchuugaka/CotEditor,eric-seekas/CotEditor,uchuugaka/CotEditor,yangchenghu/CotEditor,uchuugaka/CotEditor,eric-seekas/CotEditor,uchuugaka/CotEditor,yangchenghu/CotEditor,onevcat/CotEditor,uchuugaka/CotEditor,angi2/CotEditor,uchuugaka/CotEditor,eric-seekas/CotEditor,angi2/CotEditor,angi2/CotEditor,yangchenghu/CotEditor,uchuugaka/CotEditor,angi2/CotEditor,eric-seekas/CotEditor,angi2/CotEditor,onevcat/CotEditor,yangchenghu/CotEditor,angi2/CotEditor,yangchenghu/CotEditor,eric-seekas/CotEditor,onevcat/CotEditor,uchuugaka/CotEditor,eric-seekas/CotEditor,eric-seekas/CotEditor,eric-seekas/CotEditor,angi2/CotEditor