Completely rework of combat system:

• 1v1 instead of grouped ships fights
• true random shots
• armor does not regenerate each turn (bugfix)
• shields does break for each ship instead of "summarized shield"
• bounced shot if attack power less than 1% of enemy shield
• ships can explode if less than 70% of initial armor each round
• attack power does not range random +/-20% anymore. The randomness is high enough
• combat reports does not cut randomly (bugfix)
• optimization of arrays to Ds\Map and Ds\Vector (up to 10x less resources/time)
• tested on up to 500k units battle with success (1 core cpu, <128MB ram usage). For bigger battles the better server is needed or improve combat engine optimization.

Code require php-ds extension for array optimization. Instructions in README

Fixes jkroepke/2Moons#334