Ctrl-Enter, Ctrl-S tooltips added for Run and Save buttons

Updated code from orig branch, pencilcode-site_bug#15 (tooltips for Save and Run buttons)
to branch bug15.  Fixed tooltip text from lower case 'c' to uppercase 'C' in Ctrl-<func>.  Fixed tooltip
text Ctrl-R to Ctrl-Enter for run button.  Tested w/Chrome browser on Windows 7 host.