* Makes the HAL provide a better error message for certain things.
* Makes Java error messages better
* Updates C++ errors.
* Moves handles header folder to HAL directory
Rename the following folders:
hal/lib/Athena -> hal/lib/athena
hal/lib/Desktop -> hal/lib/sim
hal/lib/Shared -> hal/lib/shared
wpilibc/Athena -> wpilibc/athena
wpilibc/simulation -> wpilibc/sim
Windows users may need to run gradlew clean after updating.