Add protipz for hushdevz

DEVELOPING.md

@@ -11,6 +11,36 @@ To make it use as many CPU threads as you have:
 	./build.sh -j$(nproc)  # assumes linux
 	./build.sh -j8 		  # use a fixed 8 threads, more portable
 
+This is dangerous! You need about 2GB of RAM per thread, plus all the
+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.
+
+
+## Dealing with dependency changes
+
+Let's say you change a dependency and want the compile the notice. If your
+change is outside of the main Hush source code, in ./src, simply running
+`make` will not notice, and sometimes not even `build.sh`. You can always
+do a fresh clone or `make clean`, but that will take a lot of time. Those
+methods are actually best for Continuous Integration systems, but to help
+reduce the time a developer has to wait, here are some PROTIPs.
+
+
+If you are changing how a dependency is built, you should remove the entire directory like this:
+
+    rm -rf depends/work/build/x86_64-unknown-linux-gnu/wolfssl/
+
+The above will delete the entire source code of wolfssl dependency on `x86_64`
+but it will keep the tar.gz and you will not need to download it again. If
+you are testing a change in URL or SHA256, you will want to force it to download
+again:
+
+    rm -rf depends/sources/wolfssl*.tar.gz
+
+Now when you run `build.sh` again, you will be able to test your changes.
+
+
 ## Good Hygiene
 
 To avoid weird build system issues, it's often good to run: