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
The changes made in this commit do not affect any actual code,
they are purely aesthetic. I ran clang-format with google style
over all .h/.cpp files in wpilibc that weren't in wpilibC++Sim
or gtest, and the eclipse formatter over all of the Java files
using the Google eclipse formatting configuration.
Change-Id: I9627bca0bc103c398ecc1c5ba17467193291ae63