Put everything back.

ctrtool/deps/libmbedtls/BUILDING.md

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+# Building
+## Linux (incl. Windows Subsystem for Linux) & MacOS - Makefile
+### Requirements
+* `make`
+* Terminal access
+* Typical GNU compatible development tools (e.g. `clang`, `g++`, `c++`, `ar` etc) with __C++11__ support
+
+### Using Makefile
+* `make` (default) - Compile library
+* `make static_lib` - Compile library
+* `make clean` - Remove all object files
+
+## Native Win32 - Visual Studio
+### Requirements
+* [Visual Studio Community](https://visualstudio.microsoft.com/vs/community/) 2015 or 2017
+
+### Compiling Library
+* Open `build/visualstudio/libmbedtls.sln` in Visual Studio
+* Select Target (e.g `Debug`|`Release` & `x86`|`x64`)
+* Navigate to `Build`->`Build Solution`
+
+### Including libmbedtls in another VS Solution for static linking
+* Clone `libmbedtls` as a submodule into your project
+* Navigate to the `Solution Explorer` window
+* Right-click on the Solution Item and select `Add`->`Existing Project...`
+* In the filesystem popup window open `<libmbedtls location>\build\visualstudio\libmbedtls\libmbedtls.vcxproj`
+* Update each dependant project's `References` to include libmbedtls
+* Update each dependant project's `Property Pages` so that for `All Configurations` and `All Platforms` the `Addition Include Directories` has the relative path to `<libmbedtls location>\include`
+	* If `libmbedtls` is being included as a dependency in a similarly structured project the relative path is `$(SolutionDir)..\..\deps\libmbedtls\include`
+* Update the `Project Build Order` so libmbedtls is built before any of its dependants
+* Update the `Project Dependencies` so that each dependant has the box checked for libmbedtls