Issue #15663: Revert OS X installer built-in Tcl/Tk support for 2.7.6.
Some third-party projects, such as matplotlib and PIL/Pillow,
depended on being able to build with Tcl and Tk frameworks in
/Library/Frameworks.  They were unable to build with the built-in
Tcl/Tk and/or execute correctly.
merge 2.7.6 release branch
Fix test_insertwidth Tkinter tests on Tk 8.5 with patchlevel >= 8.5.12 (issue #19085).
Merge heads
Revert wrong change in previous commit (issue #19085).