Usage is:
 *    % java Tester1 hostName port namesFile concurrency delay verbose
 * where the parameters are:
 *   hostName   name of server to be tested
 *   port       port of server
 *   namesFile  file containing names of file to be retrieved, for example, 
     urls.txt 
 *   concurrent number of concurrent connections
 *   delay	    delay between successive requests on one connection in ms.
 *   verbose    either true or false: display all text that is received from
 *				server, not just the headers [CAREFULL!]
 * The program Tester1.java
 * terminates when you enter a carriage return and each thread
 * prints out the number of documents it has retrieved and how long it took.