Log Message:
Changes 8.4.8:
  * Fixed possible deadlock in Tcl_Finalize
  * Fixed thread IDs on 64-bit systems
  * Fixed [scan %ld] handling LP64 systems
  * Fixed [string map $samevar $samevar] crash
  * Fixed broken [namespace forget] logic
  * Fixed [namespace import] cycle prevention
  * Improved control over int <-> wideInt conversion
  * Fixed buffer overflow when there is a syntax error in [subst]
  * Fixed [file executable] result for case insensitivity on Windows
  * Fixed [expr {NaN == NaN}] result
  * Make [tcl_findLibrary] search $::auto_path as well
  * Fixed crash in [fconfigure -ttycontrol] in threaded build
  * [TIP 222] implementation of [wm attributes -alpha] on Windows
  * [TIP 159] implementation of [wm iconphoto]
  * Make Tk [load]-able on OS X/Aqua
  * Handle color/screen resolution changes on Windows
  * Fixed [wm resizable] for Solaris/CDE
  * Handle Windows native dialog double clicks that fall through
  * Fixed [place forget] memory leak
  * Recompute menu geometry on named font size change
  * Fixed X/IME IC focus after creation
  * Improved multiple display Tk dialog window placement
  * Fixed compound buttons for OS X/Aqua
  * Documentation improvements and test suite expansion