Arcyd: testbed: fixup repo config

Fix the test repo configs so they point to the default Phabricator
instance, follow the naming convention for config files and don't supply
an invalid GitWeb link.

Test Plan:
$ ./testbed/arcyd/loop_test.sh
$ ./testbed/arcyd/test_shell.sh
Arcyd: test_shell.sh: easy review creation

Make test review creation easier from within
    `./testbed/arcyd/test_shell.sh`
by pre-populating the test repository with a script which pushes a
review branch with a random name into the repository.

Test Plan:
$ ./testbed/arcyd/test_shell.sh
Arcyd: refactor some abdcmd's

Extract new methods from the process functions of
`abdcmd_arcydstatushtml` and `abdcmd_repostatushtml` which take explicit
parameters instead of consuming the abstract 'args' directly.

This makes it easier to implement 'arcyd instaweb'

Test Plan:
$ ./precommit.sh
$ ./testbed/arcyd/status_html_testbed.sh
Arcyd: add new command 'arcyd instaweb'

To make it easier to test and debug the web dashboard, implement a new
Arcyd command 'instaweb' which launches a webserver that will
automatically serve up arcyd status and repo status pages.

Modify the existing 'loop_test' and 'test_shell' scripts to serve up
live dashboard pages.

Test Plan:
$ ./precommit.sh
$ ./testbed/arcyd/loop_test.sh
$ ./testbed/arcyd/test_shell.sh
Visually inspect the dashboard pages