Added base HTTP request protection functionality
    
    http_shield_firefox.js - contains Firefox specific functionality
    http_shield_chrome.js - contains Chrome specific functionality
    http_shield_common.js - contains common functions used by both versions
    
    Modified both manifests to fit the new files in it, extended permissions.
    Modified Makefile, so it check for .CSV files containing IPv4/v6 locally served zones at every make
    Updated update.js with added storage keys