fixes #9108 - parent parameters are now overrideable

Fixes #11466, #11462 - Improve layout of textareas

Fixes #11467 - Textareas in form may be resized only vertically

Fixes #11461 - Remove 'global scope' column in host/hostgroup parameters form

Fixes #8785 - HTML syntax fixes - add thead/tbody, fix formatting

Fixes #4596 - Change parent of host group via AJAX

Reparenting host groups requires submitting the form to see the changes
nowadays, this fix makes the host group model inherit all properties
from the parent and show them in real time.