The path where a dynamically loaded coprocessor jar is copied on the local file system depends on the region name (and implicitly, the start key)

When loading a coprocessor from hdfs, the jar file gets copied to a path on the local filesystem, which depends on the region name, and the region start key. The name is "cleaned", but not enough, so when you have filesystem unfriendly characters (/?:, etc), the coprocessor is not loaded, and an error is thrown