Correctly parse string option values that start with + or -.

--HG--
extra : rebase_source : aa3e4a0852b4c6369ba0d753e7f3551e01c7fcf9
Recompute phase suites when options are changed.

--HG--
extra : rebase_source : f838b651f3f68aef648c34e8288cc59b0faa1ebf
Don't recreate suites on every CTW compile.

--HG--
extra : rebase_source : a211f34e4c486accb2467438bdb0cbd07e3fa10f
Truffle/Instrumentation:  Javadoc