Sync am-vector.h with AMTL (fix bug 6090).
Fix downloading of ambuild using the checkout-deps script (NPOTB).
Update checkout-deps script for Contagion on Windows (NPOTB).
Change float comparison operators to return false for NaN (bug 6107, r=ds).
Fix Windows build.
Fix Windows build, again.
Mark CS:S as supporting HudMsg (bug 6108, r=psychonic).
Fix typo pointed out by Nephrite (bug 6107, comment #7).
Update CS:GO gamedata.
Deduplicate a number of files used by extensions by moving them to the public directory (bug 5341, r=psychonic).

These files include smsdk_ext.cpp, smsdk_ext.h, sm_memtable.h, CDetour/*, and asm/*.
The smsdk_config.h file for each extension has also been moved out of the 'sdk' directory into its parent.
Trigger build for hl2sdk-csgo changes.
Fix Linux and Windows builds.
Trigger build again for hl2sdk-csgo changes.
Merge branch 'master' of hg::https://hg.alliedmods.net/sourcemod-central into develop
Some fixes for upgrade and build