HBASE-8438 Extend bin/hbase to print a "mapreduce classpath"

$ ./bin/hbase mapredcp --help
Usage: hbase mapredcp [-Dtmpjars=...]
  Construct a CLASSPATH containing dependency jars required to run a mapreduce
  job. By default, includes any jars detected by TableMapReduceUtils. Provide
  additional entries by specifying a comma-separated list in tmpjars.

$ ./bin/hbase mapredcp | tr ':' '\n'
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/netty-3.6.6.Final.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/hbase-hadoop-compat-0.97.0-SNAPSHOT.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/protobuf-java-2.5.0.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/guava-12.0.1.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/htrace-core-2.01.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/hbase-protocol-0.97.0-SNAPSHOT.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/hbase-client-0.97.0-SNAPSHOT.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/zookeeper-3.4.5.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/hbase-server-0.97.0-SNAPSHOT.jar
/private/tmp/hbase-0.97.0-SNAPSHOT/lib/hbase-common-0.97.0-SNAPSHOT.jar


git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1542811 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-YAHOO-666-trunk-gd