brunow/NoteItIOS — pull request #1 by yebing115 (2013-02-05 10:32:56+00:00)
Title: Method - (void)pushTitleLevelOnSelectedRange will sometimes throw exception when press the "#" button in editing note

In method - (void)pushTitleLevelOnSelectedRange, if selectedRange.location
is the start of the selected line, beforeTextSelection will have no content,
and [beforeTextSelection substringWithRange:NSMakeRange(0, 1)] throws exception