Bug 12658: Installter step 3 - select framework "select all" button, labels and misc...

Bug 12658: Installter step 3 - select framework "select all" button, labels and misc HTML formatting issues.

To test:
1/ Visit /cgi-bin/koha/installer/install.pl?step=3&op=selectframeworks
2/ Assert you can see a link "Select all frameworks" (with JavaScript enabled)
3/ Assert when you click the "Select all frameworks" link all checkboxes are now ticked on the page
4/ Assert when you click on the text next to a checkbox, that it will toogle the corresponding checkbox (accessibility)
5/ Assert there is less unclosed HTML tags on the page (should be none on the select framework page now)
6/ Assert the installer still functions as expected for a clean install

Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Link says "Select all frameworks"  perhaps "Select all options" or "Select all" would be clearer, but seems to work as desired

Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>