Add c++ unit tests with docs; split out ./rpctest and ./cpptest from ./test

doc/DEVELOPING.md

@@ -16,6 +16,48 @@ other programs and Operating System overhead. A good rule of thumb is:
 
 Divide how many GBs of RAM you have by 2, subtract one. Use that many jobs.
 
+# Run all tests
+
+To run both C++ and RPC tests:
+
+    ./test
+
+C++ test run much faster than the RPC tests.
+
+## Run C++ Unit tests
+
+To run the C++ unit tests
+
+    ./src/hush-test
+
+Example successful output:
+
+    Running 42 test cases...
+
+    *** No errors detected
+
+Example failure output:
+
+    Running 42 test cases...
+    test-hush/main.cpp(16): error: in "test_sodium": check init_and_check_sodium() != 0 has failed [0 == 0]
+
+    *** 1 failure is detected in the test module "HushTestSuite"
+
+# Run Python RPC tests
+
+To run our QA/functional tests:
+
+    ./rpctest
+
+Example successful output:
+
+    # Running 2 tests..
+    PASS!
+
+Example failure output:
+
+    FAIL! Number of failed tests: 1 . Details in test-1234567.txt
+
 
 ## Dealing with dependency changes