SI-6289 Partest in technicolor and showing javac errors

Paulptest includes color and simplified test scarfing.

Scalap tests are moved to the conventional name and location.

In a grouped or staged or round-robin compilation, any file foo_1.scala can contribute a foo_1.flags to the group flags. That is for simplicity.  (Mnemonic: foo declares the flags it needs, and flags are gathered on a group basis.)

Just a few fixes from the Sept 2012 version: don't apply options more than once, since multi-valued settings like -Xplugin are cumulative; honor SCALAC_OPTS because ant relies on it for -Xpluginsdir.  Note that no names have been changed to make them appear innocent.

Paul's test that compilation round errors are reported is forthcoming.

Testicolor is due to one of Paul's branches on a timeline
that apparently did not include the destruction of planet
Earth and its colonies by the Xindi.

Thanks also to Szabolcs Berecz for his merge effort.  Merging
is thankless work, but not as thankless as merging in a
timeline that actually does terminate in the destruction of
your home world and Enterprise.

Archer had a supremely difficult choice: rescue humanity or
live out his retirement with T'Pol waiting on him hand and
foot? I'm sure I don't know how I'd choose.

Review by @paulp or maybe @khernyo would also prefer that paulp kept his eyes trained on the future instead of the distant past.  It's also possible that paulp is a transdimensional being for whom time has no meaning, and who is working, as we speak, on bugs that were fixed three years ago and on features of Scala 3 that won't appear until the next decade.  Or more mysteriously, he is working on bugs that were closed as WontFix or CantFix, but which will form the basis of a future and betterized Scala beyond our ability to comprehend.