greatly simplify building

[mrexodia]

• no more hardcoded paths in the project
• more versatile .gitignore (works up to VS2017)
• include detours.lib directly in the project
• remove x64 platform (Dark Souls is 32 bit)
• remove Debug platform (the readme explicitly states this should not be used)
• add filters file to categorize source files
• added direction to DirectX SDK in the source (at the place it would error)

This conflicts/replaces pull request #33 I changed the configuration to VS2012 because that's the lowest version I could get this project to compile on.

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This change is 

[niligulmohar]

@mrexodia This is excellent! I've wanted to make this kind of cleanup, but didn't know how to do it properly. I've rebased my conflicting PR on top of this.