Support a "no_server" flag in test config.

* Will use a running instance of rippled (possibly in a debugger).
* Modify all tests to respect the server_default value.
* Fail test if new account already exists and has a balance.
* README.md with instructions for advanced test debugging, particularly using no_server.

test/README.md

@@ -0,0 +1,79 @@
+# Integration tests
+
+## Basic usage.
+
+Documentation for installation of dependencies and running these
+tests can be found with the
+[_Rippled build instructions_][unit_testing].
+(Also for [_Windows_][windows_unit_testing],
+[_OS X_][osx_unit_testing],
+or [_Ubuntu_][ubuntu_unit_testing].)
+
+## Advanced usage.
+
+These instructions assume familiarity with the instructions linked above.
+
+### Debugging rippled
+
+By default, each test will start and stop an independent instance of `rippled`.
+This ensures that each test is run against the known
+[_genesis ledger_][genesis_ledger].
+
+To use a running `rippled`, particularly one running in a debugger, follow
+these steps:
+
+1. Make a copy the example configuration file: `cp -i test/config-example.js test/config.js`
+
+2. Edit `test/config.js` to select the "debug" server configuration.
+  * Change the existing default server to: `exports.server_default = "debug";`
+  (near the top of the file).
+
+3. Create a `rippled.cfg` file for the tests.
+  1. Run `npm test`. The tests will fail. **This failure is expected.**
+  2. Copy and/or rename the `tmp/server/debug/rippled.cfg` file to somewhere 
+  convenient.
+
+4. Start `rippled` (in a debugger) with command line options
+`-a -v --conf <rippled-created-above.cfg>`.
+
+5. Set any desired breakpoints in the `rippled` source.
+
+6. Running one test per [_genesis ledger_][genesis_ledger] is highly recommended.
+If the relevant `.js` file contains more than one test, change `test(` to
+`test.only(` for the single desired test.
+  * To run multiple tests, change `test(` to `test.skip(` for any undesired tests
+  in the .js file.
+
+7. Start test(s) in the [_node-inspector_][node_inspector] debugger.
+(Note that the tests can be run without the debugger, but there will probably
+be problems with timeouts or reused ledgers).
+  1. `node_modules/node-inspector/bin/inspector.js &`
+  2. `mocha --debug --debug-brk test/<testfile.js>`
+  3. Browse to http://127.0.0.1:8080/debug?port=5858 in a browser supported 
+  by [_node-inspector_][node_inspector] (i.e. Chrome or Safari).
+
+8. To run multiple tests, put a breakpoint in the following function:
+  * File `testutils.js` -> function `build_teardown()` -> nested function
+  `teardown()` -> nested series function `stop_server()`.
+    * When this breakpoint is
+    hit, stop and restart `rippled`.
+
+9. Use the [_node-inspector UI_][node_inspector_ui] to step through and run
+the test(s) until control is handed off to `rippled`. When the request is 
+finished control will be handed back to node-inspector, which may or may not
+stop depending on which breakpoints are set.
+
+### After debugging
+
+1. To return to the default behavior, edit `test/config.js` and change the
+default server back to its original value: `exports.server_default = "alpha";`.
+  * Alternately, delete `test/config.js`.
+
+[unit_testing]: https://wiki.ripple.com/Rippled_build_instructions#Unit_testing
+[windows_unit_testing]: https://wiki.ripple.com/Visual_Studio_2013_Build_Instructions#Unit_Tests_.28Recommended.29
+[osx_unit_testing]: https://wiki.ripple.com/OSX_Build_Instructions#System_Tests_.28Recommended.29
+[ubuntu_unit_testing]: https://wiki.ripple.com/Ubuntu_build_instructions#System_Tests_.28Recommended.29
+[genesis_ledger]: https://wiki.ripple.com/Genesis_ledger
+[node_inspector]: https://wiki.ripple.com/Rippled_build_instructions#node-inspector
+[node_inspector_ui]: https://github.com/node-inspector/node-inspector/blob/master/README.md
+