Improve Debugging documentation

Author: eregon

doc/user/debugging.md

@@ -3,10 +3,14 @@
 ## Printing Exceptions
 
 There are two ways to print exceptions, which can be useful to find the source of an error:
+
 * the standard Ruby `-d` flag which print the `file:line` where each exception was raised.
 * `--backtraces-raise` which show the full backtrace on each exception raised.
 
-Both are printed even if the exception is later rescued.
+Both print all exceptions even if the exceptions are later rescued.
+
+Java exceptions can be printed with `exceptions-print-uncaught-java` or
+`--exceptions-print-java`.
 
 See other `--backtraces-*` and `--exceptions-*` options for more possibilities.