Initial tachyon-perf subproject
Add utils to parse xml
Add constants of tachyon-perf
Add PerfConf to manage configurations
Add config script
Add log4j config
Manage the configurations for each task
Add abstract classes of a task
Manage the different type of tasks
Connect with Tachyon
Add thrift component
Add client and server side of thrift
Add TachyonPerfMaster
Add TachyonPerfSlave
Add a set of file operators used for benchmarks
ListGenerator for sequential and random selection
Add tool to generate total report
Add tool to clean workspace on Tachyon
Add prototype task

This SimpleTask is an example to implement a benchmark. Also, this makes
it easy to implement other benchmarks.
Add java code of Metadata benchmark