v1.9.1

• Add source location info for define-attribute.
• Show more keys for M-x describe-bindings
• [vi-mode] improve goto-line
• Add get-prompt-input-string interface.
• improve C-x space to get in to rectangle-mode then C-t to rectangle-string are implemented.
• Fix bug 'M-x isearch' highlights. the last candidate tend not to highlight.
• Fix bug for example 'M-x isearch' find 'some' then F2(or `M-x isearch-replace-highlight') and put 'somesome'
  in the replace dialog to get into infinite loop.
• improve prompt for 'M-x query-replace'.