Log Message:
Update Tcl to 8.5.19.

Changes in 8.5.16

Changed Tcl behavior
- Unicode 7.0 charset (within BMP)
- [scan %E%G%X].
Updated packages
- http 2.7.13
- tcltest 2.3.8
- platform 1.0.13

Changes in 8.5.17

Changed Tcl behavior
- Fixed several I/O bugs introduced in 8.5.16.

Changes in 8.5.18

(none)

Changes in 8.5.19

New global variables
- tcl_platform(engine) TIP440
Changed Tcl behavior
- Update to Unicode 8.0 support.