FILEDLG95_HandleCustomDialogMessages:

FILEDLG95_HandleCustomDialogMessages:
- for the three handled messages we must return the required buffer size
- for CDM_GETFILEPATH paths like "dir\file" were handled incorrectly
- fixed multiple potential buffer overflows.
FILEDLG95_OnOpen: fixed a use of strncpy without '\0'.
FILEDLG95_SHELL_NewFolder: the size of lpstrCaption was incorrect
leading to a buffer overflow.