[Bug  3545365]: Never try a bg-flush  on a dead	channel, just like before 2011-08-17.
merge 8.5
[Bug: 3545363]: Handle socket with multiple underlying file descriptors where required (TcpCloseProc, SocketProc). Refactor socket/descriptor setup. Fix memory leak in socket close (TcpCloseProc) and related dangling pointers in SocketEventProc.
Preserve the chanPtr so that script evaluation cannot invalidate it when
we plan to use it again.
Preserve the chanPtr so that script evaluation cannot invalidate it when
we plan to use it again.
merge mark
Preserve the chanPtr so that script evaluation cannot invalidate it when
we plan to use it again.
sync with TEA, fix some comments
[Bug 3547994]: Abandon the synchronous Windows pipe driver to its fate when needed to honour TIP#398.
merge 8.5
:q!
3546275 Make [auto_execok] search match [exec].  Thanks Koen Danckaert.
3546275 Make [auto_execok] search match [exec].  Thanks Koen Danckaert.
3546275 Make [auto_execok] search match [exec].  Thanks Koen Danckaert.
update changes
merge 8.5
merge 8.5
use forward slashes in $ROOT, whenever the path is handled by tclsh/tcltest
fix TCL_LIBRARY value in "test-core" rule
merge release to dev
merge mark