Adex connector

Hi -- just added an implementation for the filtering.
Here's how I configure my client in the C++ bid_request_endpoint.cc
    for (auto & c: agent.config.creatives) {
        c.providerConfig["adx"]["externalId"] = "fashionforhome.de/70_prozent_guenstiger/728x90";
        c.providerConfig["adx"]["htmlTemplate"] = "<iframe src=\"//tracking.m6r.eu/impression/creative?creativeId=fashionforhome.de%2F70_prozent_guenstiger%2F728x90&id=adx-auction:$$AUCTION_ID$$&mbrUserId=$$MBR_USER_ID_ENCODED$$&adxPrice=%%WINNING_PRICE%%&target=%%CLICK_URL_ESC%%\" width=\"728\" height=\"90\" frameborder=\"0\" scrolling=\"no\"></iframe>"; 
        c.providerConfig["adx"]["clickThroughUrl"] = "<iframe src=\"//tracking.m6r.eu/impression/creative?creativeId=fashionforhome.de%2F70_prozent_guenstiger%2F728x90&id=adx-auction:$$AUCTION_ID$$&mbrUserId=$$MBR_USER_ID_ENCODED$$&adxPrice=%%WINNING_PRICE%%&target=%%CLICK_URL_ESC%%\" width=\"728\" height=\"90\" frameborder=\"0\" scrolling=\"no\"></iframe>";
        c.providerConfig["adx"]["agencyId"] = 59;
	c.providerConfig["adx"]["vendorType"] = "10 28";
	c.providerConfig["adx"]["attribute"]  = "7 40 94";
	c.providerConfig["adx"]["sensitiveCategory"]  = "19 10";
    }