OPENDJ-2955 Add logs to rest2ldap gateway

Logs internal server error response as error using a CHF Filter.
Split the HttpLogFilter in two parts:
    * One HttpAccessLogFilter which only logs response status in the http access log.
    * One ErrorLoggerFilter moved in opendj-rest2ldap module which performs internal server error logs.
      This filter also catch and logs runtime exceptions and then convert them in an internal server error response.
Also adds trace logs of Ldap requests and responses performed by rest2ldap.
For tomcat support, provides a logging.properties file in the servlet module in order to isolate rest2ldap logs out of the box (logs will go in ${catalina.base}/logs/rest2ldap.yyyy-MM-dd.log file)
This file does not alter Jetty logs. By default with Jetty, rest2ldap logs will be mixed with other logs (OOTB they are display in the console).