JRUBY-2724: I've added some tests and I tried to fix unc pathing
Added --profile.json to the command usage message
Profile reports can now be written to a file

Support for writing profile reports to files, notably support for writing profiles from multiple threads to the same JSON or HTML file without syntax errors.

There's a new abstraction that handles profile printing: ProfileOutput. Together with new methods on ProfilePrinter, printHeader, printFooter and a new parameter to printProfile (first), it can orchestrate the the profile printers so that they print the right things at the right time.
Added help text about the optional argument to --profile.xxx
Douglas gets points for first 1.7.0 bug!!!
JRUBY-6960 Failure to start command with conflicting directory
Add indy logic for op asgn (+=, ||=, &&=).
Remove "dynopt" mode, related code, and unused invocation logic.
Remove old defined? bytelists.
Remove unused isInvisible method.
Cull deprecations as much as possible...I can't take it anymore.
Update to 1.9.3p286 stdlib.
Update to latest 1.9.3 test suite.
Add "ruby" dir to mri19 -I flags.
Hash#initialize_copy is an alias for #replace in MRI.
Move Java-sourced dynamic call logic to MethodNames enum.
ObjectSpace tweaks:

* Check config only once and choose ObjectSpacer impl. This
avoids boolean checks along object construction paths, and allows
ObjectSpace logic to boil down to an empy inlined method when
ObjectSpace is not enabled.

* Never follow ObjectSpace-aware constructor path for Floats.
Add a common == path for Array, to avoid respond_to? checks on nil
Fix JRUBY-6949

system() silently fails when options are passed

I believe we were trying to coerce the hash args to String, which
failed...and then the failure was swallowed due to another bug
(already filed). This commit does not add options support, but
does trim them off the end of the args array and warns (once) that
they will be ignored. We plan to get the remaining process options
working in 1.7.1, and there are numerous other bugs for that.
Probable fix for JRUBY-6930

yaml escaping of non-printable characters

We need to give an encoding to the OutputStreamWriter. I chose
UTF-8 for simplicity, but that may not be quite right. Need to
decide what this encoding should be based on the target "io" we
will write to.