Bug 38089: Move style to head and correct regular expression

Bug 38089: Move style to head and correct regular expression

This patch moves the local style sections from the body to the head
where they belong and it also updates the regular expression used to
prepend the slip_id id to css selectors rather than replace them

To test:
1 - Create a new notice in the 'Patron (custom slips)' module called 'Testing'
2 - Set print content as:
    Try the  <span class="styled">styling</span> stuff.
3 - Set the 'Format' as:
    .styled {color:red;font-weight: bold;}
4 - Set system preference IntrnaetSlipPrinterJS to "//test"
    http://localhost:8081/cgi-bin/koha/admin/preferences.pl?op=search&searchfield=IntranetSlipPrinterJS
    This will prevent auto printing popup
5 - Go to a patron and click Print -> Print Testing
6 - Note incorrect styling
7 - Apply patch, restart all
8 - Print Testing again
9 - Confirm styling is correct

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>