Implemented setTaskPriority() and getTaskPriority() in Task HAL API
Removed all other unimplemented functions in HAL and removed spawnTask()
Replaced instances of pthread_t* with TASK typedef
Removed unused HAL error constants and removed commented-out classes and functions in wpilibj's HALLibrary
Changed Task class API to match the construction semantics of a std::thread
Change-Id: I3bc951a3da90d24c5589fae4d1ca2bb60225c873
Implements the JNI bindings for java
Adds integration tests for Digital Inputs and AnalogTriggers.
Adds the ability to get the value and message from errno in java using the HALUtil JNI class.
Change-Id: I853529fdab9744ce95ee15d4cc73dc3953265552
