Bug 21131: Remove the TinyMCE.isDirty() check that caused unexpected behaviour

Bug 21131: Remove the TinyMCE.isDirty() check that caused unexpected behaviour

When using the WYSIWYG editor for system preferences, the editor only
updates the textarea element if the content is different from the
original content. This means if you change a system preference and
then change it back to the original content, the textarea will have
the 2nd last change you made.

This patch removes the TinyMCE.isDirty() check, which was responsible
for comparing the original and changed content. Every input/keydown/dragend
or TinyMCE command will cause the textarea element to be updated and
trigger the input event which causes the "modified" class to be added
to the element, so that the system preference can be saved.

__TEST PLAN__

_Before applying_
0. Change "UseWYSIWYGinSystemPreferences" to "Show"
1. Change "opaccredits" to "123a"
2. Click "Save all OPAC preferences"
3. Reload the page
4. Change "opaccredits" to "123"
5. Change "opaccredits" to "123a"
6. Click "Save all OPAC preferences"
7. Reload the page
8. Note that "opaccredits" says "123"

_Apply the patch_

_After applying_
1. Change "opaccredits" to "123a"
2. Change "opaccredits" to "123"
3. Click "Save all OPAC preferences"
4. Reload the page
5. Note that "opaccredits" says "123" (and not "123a")
6. Change "opaccredits" to "1234"
7. Click "Save all OPAC preferences"
8. Reload the page
9. Note that "opaccredits" says "1234"

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit f4cf075fbea353a5cbf11aaead37c92eac8179b2)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>