Run Actors in pool do not spawn Thread per Actor
Merge pull request #66 from pitr-ch/actor

Actor improvements
Added pitr-ch as a contributer in the README.
Agent#await does not alter the value
Support sending non/blocking fns to Agent
whitespace
Merge pull request #71 from pitr-ch/actor

Support `send` and `send-off` methods for Agent
Refactored TimerTask specs.
Merge pull request #75 from jdantonio/refactor/timer-task-specs

Refactored TimerTask specs.
Prerelease 0.6.0.pre.2
Fixed brittle RubyThreadPoolExecutor spec.
IVar: move MultipleAssignmentError into the class.
IVar: documentation.
MVar: documentation.
TVar: documentation.
IVar: fix example markup.
Mutex version of atomic reference.
Changed every mutex.lock - mutex.unlock pair to ensure mutex release even with errors
closes #79
Removed ActorContext spike.
Fixed missing require in Channel.