Add max_clients parameter.
Add max_clients parameter.

This allows controlling what was the MAX_NUM_PROXY_PAIRS constant.

infinity0/flashproxy,glamrock/flashproxy,glamrock/flashproxy,glamrock/flashproxy,infinity0/flashproxy,infinity0/flashproxy,infinity0/flashproxy,arlolra/flashproxy,glamrock/flashproxy,arlolra/flashproxy,arlolra/flashproxy,arlolra/flashproxy,infinity0/flashproxy,arlolra/flashproxy,infinity0/flashproxy,glamrock/flashproxy,arlolra/flashproxy,arlolra/flashproxy,glamrock/flashproxy