Usage of pcntl_signals makes it unpossible to run on windows in the future.

[kdankert]

Describe the bug
As 0.99.22 included signal handling to shutdown the server on ctrc-c, it is not possible to run evosc in the furture as pcntl is not available on windows and won't get released as well most likely.

As pcntl is not compatible with windows, the EscRunCommand fails due to implementing the SignalableCommandInterface from Symphony.

It fails with the message Unable to subscribe to signal events. Make sure that the pcntl extension is installed and that "pcntl_*" functions are not disabled by your php.ini's "disable_functions" directive..

As it is EvoSC goal to be compatible, I suggest the fix imeplemented in the attached PR.

Expected behavior
EvoSC should not fail to start because of pcnt extensions not being loaded. Instead workarounds or windows alternatives should be used on windows.

EvoSC (please complete the following information):

• EvoSC-Version: [e.g. 0.87.x] (get with php esc version) 0.99.22
• Game: TM2020

When using git (please complete the following information):

• Current-Commit: [e.g. bb3eefb] (get with git rev-parse HEAD) 8a220f1