Fix elscreen-save-screen-excursion messing with window histories.
See http://www.gnu.org/software/emacs/manual/html_node/elisp/Window-History.html
it now restores window histories only when the Emacs running it supports window histories.
Readme: add my name to "Acknowledgement" :)
Merge pull request #6 from debug-ito/fix_window_history

Fix elscreen-save-screen-excursion messing with window histories