Remove extra space
Use OneToOne for parent wormhole in wormhole model

Related name has changed from parent_wormholes to parent_wormhole. This
means that querysets do not need to be constructed for this connection and
select_related can be used.
Use builtin variables for System inheritance

Django caches these behind the scenes rather than hitting DB each time
System.get_spec() is called
Use select_related() in system_tooltips() view
Fix templates

The system_detail templates were still accessing parent_wormholes not
parent_wormhole
Fix system_menu template
Merge pull request #47 from joshuablake/systemTooltip

System Tooltip Optimisation