Do not use github.com in tests.

Two tests were spuriously failing because they tried to load pages on
`github.com` that were no longer structured as expected.  Use a local
webserver instead.

 #12230 (Test suite improvements).
Eliminate console spam during normal test execution.

Three tests were (potentially) dumping text to console.log during the
run, which they should never do.

Fixing that revealed that one of them, the test for interrupting a
long-running JS script, was not actually testing what it was supposed
to test. Fixing *that* revealed that the long-running-script hook is
broken and does not actually interrupt JS infinite loops; that test
has been temporarily disabled.

 #12230 (Test suite improvements).
Import Jasmine 1.3.1.

 The newer jasmine-console behavior requires minor adjustments to the
 ConsoleReporter we create in run-tests.js.  Also, en passant fix for
 a bug in the final callback: exiting with status equal to the number
 of failed tests does not work, because the _exit() system call takes
 only the low eight bits of the value passed.  If a test run happened
 to have 256 failing tests, the old code would have spuriously exited
 successfully.  Instead, just exit(1) if any tests fail.

 #12230 (Test suite improvements).
Fix jasmine.ConsoleReporter.specFailureDetails.

The new Jasmine includes a version of this formerly external add-on, but it
is buggy and doesn't print details of failing tests.

 #12230 (Test suite improvements).
Add ability to run tests selectively.

 * Anything on the command line after "run-tests.sh" will be understood
   as a regular expression (if there is more than one argument, they are
   concatenated, with spaces in between) and only the tests whose "full
   names" match that regexp will be run.  The full name of a test is the
   "describe" string plus a space plus the "it" string.  Note well that,
   unlike the test-runner output, there is no colon in there.

 * run-tests.sh and run-tests.js now correctly handle being invoked from
   an arbitrary directory; the cwd does not have to be the project root.

 * Shell portability fixes for run-tests.sh.

 #12230 (Test suite improvements).
Add a -v/--verbose option to run-tests.{sh,js}.

The newer ConsoleReporter is very quiet by default, which is nice, but
this provides a way to get something more like the older one-line-per-test
output.

 #12230 (Test suite improvements).