[krbdev.mit.edu #5613] NIM GUI: views jump around on the screen

[Jeffrey Altman via RT]

This patch is functionally correct.  There are some style issues:
(1) I prefer main_wnd_save_sizepos() to be static since it is not used
outside the source file.

(2) I prefer that main_wnd_save_sizepos() not be called from within
khm_set_main_window_mode() if the main application window has not been
created.

(3) the reason that main_wnd_save_sizepos() must be called before
khm_main_wnd_mode is updated is subtle and should be documented.

I will move this ticket to the krb5 queue and then commit the patch with
my style changes.