HBASE-20833 Modify pre-upgrade coprocessor validator to support table…

… level coprocessors

- -jar parameter now accepts multiple jar files and directories of jar files.
- observer classes can be verified by -class option.
- -table parameter was added to check table level coprocessors.
- -config parameter was added to obtain the coprocessor classes from
  HBase cofiguration.
- -scan option was removed.

Signed-off-by: Mike Drob <mdrob@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/tool/PreUpgradeValidator.java

@@ -65,9 +65,9 @@ public void setConf(Configuration conf) {
   private void printUsage() {
     System.out.println("usage: hbase " + TOOL_NAME + " command ...");
     System.out.println("Available commands:");
-    System.out.printf(" %-12s Validate co-processors are compatible with HBase%n",
+    System.out.printf(" %-15s Validate co-processors are compatible with HBase%n",
         VALIDATE_CP_NAME);
-    System.out.printf(" %-12s Validate DataBlockEncoding are compatible on the cluster%n",
+    System.out.printf(" %-15s Validate DataBlockEncodings are compatible with HBase%n",
         VALIDATE_DBE_NAME);
     System.out.println("For further information, please use command -h");
   }
@@ -104,8 +104,10 @@ public int run(String[] args) throws Exception {
   public static void main(String[] args) {
     int ret;
 
+    Configuration conf = HBaseConfiguration.create();
+
     try {
-      ret = ToolRunner.run(HBaseConfiguration.create(), new PreUpgradeValidator(), args);
+      ret = ToolRunner.run(conf, new PreUpgradeValidator(), args);
     } catch (Exception e) {
       LOG.error("Error running command-line tool", e);
       ret = AbstractHBaseTool.EXIT_FAILURE;