build: Fix linux script & change build script naming

gen-windows.bat

@@ -0,0 +1,23 @@
+@echo off
+
+REM CI uses pre-built Boost
+IF "%CI%"=="" (
+	REM Create build dir
+	mkdir src\external\boost-build
+	cd src\external\boost
+
+	REM Build our Boost subset
+	b2 -j5 --build-dir=../boost-build --stagedir=../boost-build stage
+	cd ../../..
+)
+
+REM Generate project files
+mkdir build-windows
+pushd build-windows
+
+IF "%CI%"=="" (
+	cmake -G "Visual Studio 15 2017 Win64" ..
+) ELSE (
+	cmake -G "Visual Studio 15 2017 Win64" -DCI:BOOL=ON ..
+)
+popd