Release v0.8.4

 update version (rcmdnk)

 fix Esc to Normal (rcmdnk)
 refactoring HandleXXX functions (rcmdnk)
 add options VimSendEscNormal/VimSendCtrlBracketNormal to send original key in the normal mode (rcmdnk)
 make consistent descriptions for modes (rcmdnk)
 update readme (rcmdnk)
 update settings picture (rcmdnk)