Various bits of cleanup, efficiencies, and comment documentation in tclVar.c
Backported [Bug 2882342]: correct struct _REPARSE_DATA_BUFFER  in tcl 8.4
merge-mark
Test for Bug 1884496 (not buggy on trunk).
Put back TclBackgroundException in internal stub table, so extensions using this, compiled against 8.5 headers still run in Tcl 8.6.
If TCL_NO_DEPRECATED is defined, make sure that TIP #139 functions all are taken from the public stub table, even if the inclusion is through tclInt.h.
If TCL_NO_DEPRECATED is defined, make sure that TIP #139 functions all are taken from the public stub table, even if the inclusion is through tclInt.h.
Clarify readable fileevent "false positives" in	the case of multibyte encodings/transforms [Bug 3436609].
Various bits of cleanup, efficiencies, and comment documentation in tclVar.c
Various bits of cleanup, efficiencies, and comment documentation in tclVar.c (from mig-review)
merge trunk