Clang format

This patch adds a clang format so that all commits adhere to the same coding style. I was finding the style varying quite a bit throughout the c++ code so thought it's about time to standardise it a bit.

The .clang-format is a Qt style format based off the LLVM style and looks similar to what you will see looking through the Qt source.

There is also a couple of helper scripts to setup a git pre commit hook so that it can get applied before each commit as well as a script to apply the style to staged changes manually.

All it requires is each dev to install clang-format on their Dev environment and ideally setup the git hook.