[paho-dev] New Makefile for building C client

[Ian Craggs <icraggs@xxxxxxxxxxxxxxxxxxxxxxx>]

I've created a new Makefile for building the C client, in the root directory of the C project on Linux.  I've attempted to conform to as many standards as I could find, like:

http://www.gnu.org/prep/standards/html_node/Standard-Targets.html
http://l4u-00.jinr.ru/usoft/WWW/HOWTO/GCC-HOWTO-6.html

It adds library versioning, targets for install/uninstall, clean and doc.

I intend to do the same for MacOS.  For Windows, I'm planning a Visual Studio project and Ant for automated builds.

I think that will cover the major platforms of interest for now.

Ian