More frequent, smaller hardforks vs. less frequent, larger ones

[axic]

I suggest to use Devcon locations past Istanbul:

• (devcon 0: berlin?)
• devcon 1: london
• devcon 2: shanghai
• devcon 3: cancun
• devcon 4: prague
• devcon 5: osaka

After 2.5 (?) years that would mean we need to have more devcons or switching naming convention