Upgrade to VS 2012, command-line builds, Reflective DLL update and removal of many warnings

This PR contains quite a few changes which fit into the following categories:

* Update to Visual Studio 2012 toolset.
* Allow building with Express edition of 2012.
* Enable command-line builds for later integration in a CI setup.
* Update of Reflective DLL Injection to include Stephen Fewer's most recent changes around Windows RT / ARM
* Bug fix for pointer truncation problem.
* Tidying of code to remove warnings, many of which come about as a result of compiling with a C++11 compiler.
* Ignoring editor-related files in .gitignore.

Apologies for the epic PR, I did quite a bit of work without thinking of merging. I hope it's not too much of a pain to merge.

I look forward to your feedback. Cheers!