Various bits of cleanup, efficiencies, and comment documentation in tclVar.c
Turn pkgb.so into a Tcl9 interoperability test library: Whatever Tcl9 looks like, loading pkgb.so in Tcl 9 should either result in an error-message, either succeed, but never crash. 
Eliminate unnessarcy static HasStubSupport() and isDigit() functions, just do the same inline.
Make pkgb.so loadable in Tcl 8.4 as well. 
Eliminate unnessarcy static HasStubSupport() and isDigit() functions, just do the same inline.
Inline compat Tcl_GetDefaultEncodingDir. 
Eliminate unnecessary static HasStubSupport() and isDigit() functions, just do the same inline.
merge release
Stop leaking allocated space when objifying a zero-length DString. [Bug 3598150] spotted by afredd.
Change back to using an isDigit function. We simply don't need to make any
(formally non-portable) assumptions about what happens when an unsigned zero
is decremented, and the code isn't in a performance-critical area.
merge trunk
eliminate dependancy of compat/*.h on tcl.h
eliminate dependancy of compat/*.h on tcl.h
proposed fix for Bug 3598300
[Bug 3598580]: Tcl_ListObjReplace may release deleted elements too earl
[Bug 3598580]: Tcl_ListObjReplace may release deleted elements too early
[Bug 3598580]: Tcl_ListObjReplace may release deleted elements too early
restore old refcounts in TCL_ERROR case.
For Tcl9, do a real Tcl_DecrRefCount
restore refcounts as they were before the Tcl_ListObjReplace call, in the error situation.
In Tcl9, make this a true Tcl_DecrRefCount, which properly cleans objects with refCount 0
restore refcounts as they were before the Tcl_ListObjReplace call, in the error situation. 
In Tcl9, make this a true Tcl_DecrRefCount, which properly cleans objects with refCount 0
Working towards more efficient treatment of non-bytecoded ensemble subcommands.
Marked some string subcommands as obsolete, following discussion on tcl-core.