v.5.20.0

Windows version 5.20.0 crashes, expect an update soon

Moderately revised the manuals

DISCUS
Added a logical function to test the status of atom properties

DIFFEV
Modified the writing of "diffev_best", the final "exit" at the end of the macro has been discarded

LIB_F90
added the option to toggle the wait command on/off

MIXSCAT
updated , no functional changes

CYGWIN
put installation scripts up to date