Revert "Route unhandled Chokidar errors to log.debug (Fixes #959)"

This reverts commit 7946acc63f936c73abc7154184e5b68134c0156a.
fix: don't crash/terminate upon errors within chokidar

Handle errors from chokidar and route them to the console. Previously,
these unhandled errors (which are very common when editing in Visual
Studio) would cause karma to terminate and all browsers to vanish. Fixes
#959