add parameters providing allocation width and height without scrollbars

add parameters providing allocation width and height without scrollbars

* shell/ev-view.c (ev_view_best_fit, ev_view_fit_width): add
parameters providing allocation width and height without
scrollbars and width of a possible vertical scrollbar. With this
additional information the functions can work as
intended. Unfortunately they're not idempotent. We should
transform these commands to toggles. Fixes Bug #164976
Initial patch by Stephane Loeuillet, then heavily modified.

* shell/ev-view.h: update prototypes.

* shell/ev-window.c (ev_window_cmd_view_best_fit)
(ev_window_cmd_view_page_width): provide EvView fit functions with
all the information they need. Formulas to calculate this
information taken from GtkScrolledWindow.