#5 Stance functions cannot pause threads

[Delano]

The tkMV_PAUSE_THREAD flag used with playerStance() or itemStance() does not pause the thread; thread execution resumes whilst the stance is animating. To reproduce:

1. Create a custom animation for an item and assign.
2. Create a program that calls itemStance() on the custom animation and includes the tkMV_PAUSE_THREAD flag, and add commands after this line, such as mwin() calls.
3. Place the item on a board and assign the above program to its multitasking slot (its thread).
4. Run the board: the item's thread begins the custom stance animation but subsequent commands are executed before the animation finishes. The tkMV_PAUSE_THREAD flag should cause the thread to pause execution until the animation finishes.