Add CLI demo application

The demo application currently doesn't connect to the database,
however it does demonstrate the interface between user and database.
Eventually, commands will be sent to the database as well.
Add Serialization to Records

This patch utilizes Boost Serialization to allow for simple and
efficient serialization of the Record class thus allowing an easy way
for the data to persist on disk.
Merge pull request #30 from vmrob/boost-modules

Add boost dependencies
Merge pull request #31 from vmrob/record-serialization

Add Serialization to Records
Merge pull request #29 from vmrob/cli-application

Add CLI demo application
Add Datastore

This patch adds the Datastore class and provides methods to retrieve
a key given the path to the key. Per the design document, the
datastore has the responsibility of managing the disk storage as it
relates to the records.