Ie8 fixes 9771

[will-moore]

This fixes a couple of issues in IE8:
See: https://trac.openmicroscopy.org.uk/ome/ticket/9771

To test (on IE8):
Right-click menu on the P/D/I tree - check that disabled items appear disabled and that sub-menus of disabled items look OK too.
Check that P/D creation works OK, new P/D inserted into the tree etc.

[atarkowska]

those works ok, but refresh button failed on

SCRIPT5007: Unable to get value of the property 'split': object is null or undefined 
webclient, line 1700 character 9

basically there is not spinning wheel while refresh. This seems to be IE issue, also in IE9

The same issue on FF

TypeError: get_selected.attr(...) is undefined
if (get_selected.attr('id').split("-")[0] === 'plate') {

[will-moore]

@aleksandra-tarkowska Thanks - should be fixed now.

[atarkowska]

Works fine, there is another issue with spinner, but I will open separate PR for that. Ready to merge

[will-moore]

--rebased-to #1760