The patch adds support for Chinese dates in diary, in which the cycle
and year are concatenated as cycleyear i.e. cycle 78 and year 31 is
represented as 7831. The following commands are available in the
calendar window:

 KEY      COMMAND
 ======   ======================================
`i C a'   diary-chinese-insert-anniversary-entry
`i C d'   diary-chinese-insert-entry
`i C m'   diary-chinese-insert-monthly-entry
`i C y'   diary-chinese-insert-yearly-entry
 ======   ======================================