OPENDJ-1635 SNMP: fail to get dsServerDescription value

SNMP's dsServerDescription determines the install path from the location of bootstrap-client.jar, extracted from the class path.
However, start-ds command uses bootstrap.jar in the classpath instead of bootstrap-client.jar (which is for the tools).
The fix consists in verifying the location for both boostrap.jar and boostrap-client.jar in the classpath.


Installation.java:
Changed OPENDJ_BOOTSTRAP_JAR_RELATIVE_PATH to refer to bootstrap.jar.
Added OPENDJ_BOOTSTRAP_CLIENT_JAR_RELATIVE_PATH constant.

Utils.java, Utilities.java:
In getInstallPath(), added checks for both OPENDJ_BOOTSTRAP_JAR_RELATIVE_PATH and OPENDJ_BOOTSTRAP_CLIENT_JAR_RELATIVE_PATH.