Remove scaladoc deprecated option.

Remove -external-urls that had been previously deprecated in 2.10.
Merge pull request #2338 from som-snytt/issue/7314-test-tools-jar

SI-7314 Partest locates tools.jar and javac
Merge pull request #2382 from vigdorchik/remove_scaladoc_deprecation

Remove scaladoc deprecated option.
SI-7358 Partest fails on scalacheck failure

A failing test generates a test failure.
The failure log is added to the transcript.
The log stream is closed when done.
Partest testnum field width is sensitive to total tests

Allow the hyphens to line up on a column within the output
for a test category or "kind".

```
$ partest files/neg/t4134.scala --run
Selected 1348 tests drawn from 1 named test categories, specified tests

& starting 1 test in neg
ok 1 - neg/t4134.scala

& starting 1347 tests in run
ok    1 - run/absoverride.scala
ok    2 - run/amp.scala
ok    3 - run/adding-growing-set.scala
```
SI-7349 Partest supports test-interface

This commit updates Scalacheck to 1.10.1 and invokes it using the
test-interface API.  This obviates kludgy output checking for result
status.

The context class loader is set to a loader that the scaladoc scalacheck
tests can use, but those tests don't need to be scalacheck tests (as they
merely assert a predicate).  A useful refactor would reunite the source
submitted to scaladoc and the test making an assertion about the result,
but that must wait for GUTtest, which should run scaladoc the way
scalac is currently run in compilation rounds.
Partest has an optionable wait period.

Partest --timeout "30 seconds" to time out the test run.

It will not hang on timeout ("I hang with Par-Test" t-shirts
not-withstanding).

It's beyond the scope of this commit to investigate argument
parsing:

`partest --timeout "\"30 seconds"\" --pos`