Bug 12056: fix untranslatable strings in calendar

In the calendar there are some strings in a JavaScript function which
are not properly wrapped in a function for translation. This patch
corrects this.

This patch also corrects some minor validation issues and spelling and
grammar issues, including those covered by Bug 12055.

To test, apply the patch and view the calendar in Tools -> Calendar.
When you hover your mouse over a day in the calendar you should see a
title tooltip indicating what kind of day/holiday it is and showing the
title of the holiday, if any.

To test that the strings are now being picked up for translation,
run translate update on a po file and confirm that the affected strings
are now present: "Weekly holiday," "Yearly holiday," etc.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>

Works well. New strings on translation file. No koha-qa errors.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, passes all tests and QA script.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 0837954cdda85549f5552dacefd3a5bc3e58292e)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>