Fix string copy in egs++ advanced application
Fix string copy in egs++ advanced application

Use the C++ string copy function instead of strcpy. The latter adds a
terminating null character to the character array which interferes with
contiguous character arrays in COMMON blocks or C data structures, such
as the_media->pxsec and the_media->eiixsec.

marenaud/EGSnrc,mchamberland/EGSnrc,ftessier/EGSnrc,ftessier/EGSnrc,MartinMartinov/EGSnrc,MartinMartinov/EGSnrc,MartinMartinov/EGSnrc,mchamberland/EGSnrc,ftessier/EGSnrc,nrc-cnrc/EGSnrc,ftessier/EGSnrc,marenaud/EGSnrc,mchamberland/EGSnrc,MartinMartinov/EGSnrc,crcrewso/EGSnrc,nrc-cnrc/EGSnrc,marenaud/EGSnrc,MartinMartinov/EGSnrc,crcrewso/EGSnrc,ftessier/EGSnrc,marenaud/EGSnrc,mchamberland/EGSnrc,nrc-cnrc/EGSnrc,nrc-cnrc/EGSnrc,crcrewso/EGSnrc,marenaud/EGSnrc,ftessier/EGSnrc,crcrewso/EGSnrc,mchamberland/EGSnrc,crcrewso/EGSnrc,marenaud/EGSnrc,mchamberland/EGSnrc,nrc-cnrc/EGSnrc