Build script and main for Indexer

Build script can be used to build both Indexer and Projector using

./build.sh indexer
./build.sh projector
./build.sh            (builds everything)
./build.sh clean      (clean up)

By default, it will build both. Binaries will be placed under bin.

Change-Id: I337a8c01173cbc4bf67f5d4db2dfb781fb91e069
Reviewed-on: http://review.couchbase.org/38871
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Tested-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>