Changed context menu DesktopWindows a bit

This is necessary because if a mod ( in test case - PAC3 ) adds a custom
button under "Player Model", it will block the top of context menu from
being clickable  when holding C button.
Added right click menu for spawn menu headers

So you are able to delete them.
Added a setting to loop sequences

I couldn't find a better way to use a sequence as an idle animation. As it's only a minor change and adds functionality, I think it'd be more useful in here that as its own task.
Revert "Changed context menu DesktopWindows a bit"

This reverts commit d7753fd5e036f05e20080ce483ba45cd800820fa.
Added list.contains
Materials: Make sure this is in the 'allowed' list in multiplayer - to stop people using exploits
Cleaned material.lua
This doesn't actually work.
Fixed string.FormattedTime returning incorrectly in some cases

Hours and minutes may have been fixed in 157 yet the seconds rounding problem still existed.
Seconds has now been properly floored.
Fixed zoom reset

Zoom reset was fetching wrong data serverside.
Merge pull request #75 from Python1320/patch-1

Fixed zoom reset
Merge pull request #73 from Bacon-Man/patch-1

Fixed string.FormattedTime returning incorrectly in some cases
'lua_find' can now be used from a server console without erroring
Merge pull request #80 from samuelmaddock/master

'lua_find' fixed for use in the server console
Merge pull request #45 from NullEntity/patch-2

Added a setting to loop sequences
Merge pull request #38 from robotboy655/master

Added right click menu for spawn menu headers
TTT: Add crosshair size and brightness settings

By request, settings to make the crosshair more visible.
TTT: Add hook for adding settings
TTT: Add hook for overriding karma kick
fixed resetting material with material tool