Bug [3598282]: Stop using installData.tcl to install the timezone files.
Branch for fixing 3602706
cherry-pick [0f098031c3]
re-apply [8aca9a8e96], while backporting [d91c86d0da] from trunk.
This fixes bugs #3601260 and #3602706
More symmetric Tcl_(Incr|Decr)RefCount call, preventing bugs like #3601260 and #3602706
Eliminate all Tcl_ConvertToType calls and all direct calls to typePtr->setFromAnyProc (except the call from inside the Tcl_ConvertToType function) from the Tcl core.
[3603163]: Stop crash in weird case where [eval] is used to make [array set]
get confused about whether there is a local variable table or not. Thanks to
Poor Yorick for identifying a reproducible crashing case.
Cherrypick the refcount fixes and comments from mig-review.

I also find the revised "createPart2" values in *Lookup* calls appealing,
but I'm too fearful of breaking things without understanding the implications.
This approach just focuses on fixing the things I broke, without trying
to "fix" things long "broken" in multiple years of releases.
Cherrypick again.  Add test.
Fix for Bug 3602706.
Merge in fix for 3602706
merge trunk