#71 Restore lastview file on launch option

[cory1492]

Since it is saving the lastview file info so it
restores your position when opening the last file you
viewed, why not add the option to restore the file when
starting bookr wrather than going to the default menu
and forcing the user to open the file manually?
(my guess is this is the plan, but I personally would
like to see it if it is not)

-as an option because PDF can take such a long time to
render upon opening.