Trying to benchmark RPC slowdown when using many tiles.

Add timer helper to track time spent in various methods.
Add FastRLock which supposedly is quicker for non-contended regions.

Add simple benchmark which just runs a map over a small amount of data.
Use a fixed array size to avoid confusion.
Merge pull request #81 from spartan-array/rpc-benchmark

Trying to benchmark RPC slowdown when using many tiles.