Fixed a defect in iosrv.exe that caused a panic if a foreground read object was attached to a different end point. This was due to the read object being notified of a change in foreground before its iEndPoint member was updated. This member is now updated before attempting the attach, and is set to NULL in the event of a leave (resulting in the read object being left in an unattached state). Also tweaked ymodem.cif to make it more readable.

---------------------------- Test U1 ------------------------------
1:X one
2:X two3:X three4:X four
5:X five
6:X six
7:X seven…8:X eight
9:X nine
10:X ten
---------------------------- Test U2 ------------------------------
12-Before 111
13-Before 222
14-Before 333…15:Match
16-After 111
17-After 222
18-After 333