Fixes artf4809.
In both C++ and Java, error messages are being sent to both the console
(via stdout/stderr) and being reported via the HAL. We don't want to
remove the stdout/stderr reporting at present because users debugging only
via netconsole (e.g. using riolog) won't see the HAL-reported errors. Until
there's an alternative means to getting the HAL-reported errors to those
users, instead store the previous 5 error messages and don't duplicate them
more often than once per second.
Changes the error reporting from setErrorData() to sendError(), which
improves driver station error reporting. The "location" in C++ is given as
the immediate caller (e.g. the WPILib function). The "location" in Java is
given as the first user function in the call stack. Note the full call stack
is provided in both instances.
Change-Id: I590dd63dcb66825301ebb260aff00cd8d7d501ed
3c3b2c75c0