Use a fixed number of sysv semaphores.

This allows us to leave them open and save some resources, while
enforcing a cap on the number of open semaphores at any time.

Also makes the clear_stale_sysvsems script obsolete.
Merge branch 'v0.12.0-hotfixes' into staging
Fix: API link in help page.
Add loadout attributes API call.
Fix: actually enforce the 50 attribute limit.
Add more custom attributes.
add damage, tank, and outgoing to loadout attributes api
documentation for new computed ship attributes
new reload parameters
Adjust outgoing numbers to real values
Support passing a custom damage profile in loadout_attributes.
Refactor API calls caching.

Also fix get_fit_from_input_post_get() not checking loadout
visibility.
Overhaul/refactor API documentation.
Fix: use new help URIs in the sitemap.
Fix: actually use module index in get_unique().
Add rehash fittings scripts; parallelize delta reformatting.
Merge branch 'master' into staging

Conflicts:
	UPDATING
	inc/state-cache.php
	src/dispatch.php
	src/md/api.md
Fix: use correct syntax of make_list().
Fix: add noindex on cast flag pages.
Update guidelines with DOM usage.