Bug 10052: Make intranetstylesheet and intranetcolorstylesheet behave exactly like...

Bug 10052: Make intranetstylesheet and intranetcolorstylesheet behave exactly like their opac counterparts

Allow a relative path (within theme/css) in intranetstylesheet too.
Allow a full path, local or remote with http(s), in intranetcolorstylesheet.
This restores consistency between opac and staff.

Test plan:
First: the patch with the db revision should have been applied. And also the
updatestructure step from the web installer should have been run.

Clear intranetstylesheet. Check included stylesheet with page source in browser.
Enter a full path with http or / in intranetstylesheet. Check again.
Enter a relative path (such as staff-global.css). Check again.

Clear intranetcolorstylesheet. Check if there is no reference with page source.
Enter a full path with http or / in intranetcolorstylesheet. Check reference.
Enter a relative path (such as blue.css). Check again.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>