New physics for bazza's gpl 67 mod 1.2

This updates bazza's gpl 67 mod for AC
changes include
1. increased grip
2. better default setup
3. increased car weight (assume driver's weight is 70kg)
4. decrease BRM's engine volumn (requires CSP)
5. AI brakes more efficiently

in general, cars are faster and AI at 100% difficult can do lap times like in real life 1967 GP. For Lotus 49, its lap time by AI also matches that of Kunos Lotus 49

Note: Kyalami had been widened and resurfaced in 1968, the one in AC should be considered the 1976 version (see AMS 2) and is faster than the 1967 version. Zandvoort by Sergius Loro has more track grip than usual (1.04). if track grip is lowered to 0.975 like other tracks, then the lap time by AI is correct

To install unzip to the steam folder (for example: C:\Program Files (x86)\Steam\SteamApps\common\) then go to each folder of the cars (for example assettocorsa\content\cars\gpl67_ferrari_312\data) and delete or rename data.acd

This is an offline mod, if you want to play with it online, everyone must also install it.