(lispy_mouse_names): Variable removed.

(lispy_mouse_names): Variable removed.
(Vlispy_mouse_stem): New variable.
(syms_of_keyboard): Initialize Vlispy_mouse_stem.
(make_lispy_event) <mouse_click, scroll_bar_click>: Don't abort
for any mouse button number.  Increase size of mouse_syms and
button_down_location as needed.  Call modify_event_symbol with
different arguments.
(make_lispy_event) <scroll_bar_click> [USE_TOOLKIT_SCROLL_BARS]:
Call modify_event_symbol with different arguments.
(make_lispy_event) <w32_scroll_bar_click> [WINDOWSNT]: Don't abort
for any button number.  Call modify_event_symbol with different
arguments.
(modify_event_symbol): Rename NAME_ALIST to NAME_ALIST_OR_STEM.
Accept a string for NAME_ALIST_OR_STEM.