Phoenix-180

A fresh pull request with all the changes for guideposts. 
Tested in a single cluster for different combinations. 
"SELECT count(*) FROM  %s WHERE host='CS' AND domain='Apple.com' AND FEATURE >= 'Dashboard' AND FEATURE <= 'Report';" % (table)) 
With 5000000 rows
Withoutpatch
===========
COUNT(1)
----------
    555169
Time: 2.264 sec(s)
Withpatch
=========
  COUNT(1)
----------
    555169
Time: 0.813 sec(s)

Withoutpatch
==========
  COUNT(1)
----------
   1002201
Time: 1.889 sec(s)
Withpatch
==========
  COUNT(1)
----------
   1002201
Time: 1.075 sec(s)

Am sure we would get better results if we are able to tune the guidePosts width so that instead of fetching in the range of 1000s inside a region we can fetch 10ks of result in every chunk.  Also should work with bigger tables and more rows.
The tests were performed with 256*1024 and 1024 * 1024 as the guidepostsWidth size. 
The main thing you can observe in the above case is that the query targetted to single region is parallelized and distributed to smaller chunks and so the work done by every thread is less. 
I think NOT only analyze even when major compation happens we need to delete the older guide posts.
Currently we have HTable.rowMutate() where we could add different mutations for the same row. (Put and delete).  So we would like to issue the delete for the row key with tablename, family and region name and then create the put with the latest stats in the same rowMutate(). But as we don't know the ts of the latest rowkey if we just issue a Put and Delete it would mask even the latest one. Hence it we have to issue deleteColumn(fam, qual) for every qualifier in the table and then add the put to the RowMutation object. The point to be noted here is that deletecolumn(fam, qual) is costly as it tries to get the latest ts before actually deleting the column.