Log Message:
Changes 8.4.9:
* Fixed segfault in info vars trivial matching branch (new in 8.4.8)
* Fixed the treatment of backslashes in file join on Windows
* Improved readdir_r detection and usage on unix
* Fixed potential unix fileevent issue on 64-bit systems
* Remove file normalize on tcl_findLibrary search path uniqification
  added in 8.4.8
* Ensure tilde paths are not returned specially by 'glob'
* Fixed clipping of partially transparent images on buttons on unix to
  avoid X error
* Fix Tk_PhotoPut(Zoomed)Block overlay compositing of partially
  transparent areas on blank targets