Add a very brief blurb on packages needed for compiling
The following packages are required for mosquitto:

tcp-wrappers (optional, package name libwrap0-dev)

To compile, run "make".

tcp-wrappers support can be added by editing config.h to comment out the
appropriate #define lines.

Use cmake to compile on Windows.

If you have any questions, problems or suggestions (particularly related to
installing on a more unusual device like a plug-computer) then please get in
touch using the details in readme.txt.
