Supports opening failing tests in browser.

Tests based on TortoiseFinder and DockingSuite write their JS output to
a file (on test failure).

Use `browseFailures` in SBT after a failing test run to open a page
reporting the failing tests.

Extracts TortoiseFinder from TortoiseFixture.
Merge pull request #106 from NetLogo/wip-test-in-browser

Wip test in browser