Merge branch 'master' of https://git.hush.is/hush/hush3

INSTALL.md

@@ -4,7 +4,7 @@
 
 To install a Debian package:
 
-	dpkg -i hush-3.5.0-amd4.deb
+	dpkg -i hush-3.6.2-amd4.deb
 
 To uninstall:
 
@@ -42,6 +42,18 @@ cd hush3
 ./build.sh -j$(nproc)
 ```
 
+## Building On Ubuntu 16.04 and older systems
+
+Some older compilers may not be able to compile modern code, such as gcc 5.4 which comes with Ubuntu 16.04 by default. Here is how to install gcc 7 on Ubuntu 16.04:
+
+```
+sudo add-apt-repository ppa:ubuntu-toolchain-r/test && \
+apt update && \
+apt-get install -y gcc-7 g++-7 && \
+  update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 60 && \
+  update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 60
+```
+
 ## Run a HUSH Node
 
 ```sh