Thrift: Revamp build to use a single configure.ac.

Thrift: Revamp build to use a single configure.ac.

Summary:
Ben Maurer suggested that it would make sense for Thrift to build as
a single project, with one configure.ac and multiple Makefile.am.
He was also kind enough to do the heavy lifting, and this commit
is the application of his patch (with minor modifications).
The most significant visible change from this diff is that
in order to buidl one of the thrift sub-projects (i.e.: the compiler,
the C++ library, or the Python library) you must run bootstrap.sh
and configure in the Thrift root, then make in the specific project.
Users who want to build and install the Python library but
can't run configure because they don't have Boost can simply
run setup.py directly.

Reviewed By: mcslee

Test Plan: Built Thrift from scratch.

Revert Plan: ok

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665409 13f79535-47bb-0310-9956-ffa450edef68