Add the multi precision int library from boost.

This library provides the exact API and functionality we need for decimals.
I've included a simple example of how the API is used. Still looking into
the perf but I don't think we can build something much faster as easily.

I've taken the latest version from boost 1.55 but I don't think we can
upgrade that in all of our supported platforms easily. Instead I've taken
this part of the library and put it in thirdparty.

Change-Id: Icf9879d546aa6a8bde046940fb91eb5060fb2f47
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1691
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: jenkins