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
Modules aren't used anymore in wpilibc and wpilibj, so the hal functions
that references them and and JNI bindings for these functions have been
pulled out.
Both Counter classes were also modified because they still referenced
modules.
Change-Id: Ic01feb145a4ed5f08cd55f140867c721f5ee7b10
