Add build scripts for macOS and Windows

tools/GenerateImportLibraries.ps1

@@ -0,0 +1,35 @@
+Param(
+    [Parameter(Mandatory, Position = 0)]
+    [string]$architecture
+)
+
+Function Convert-DLL([string]$name)
+{
+    & gendef.exe "..\..\bin\$name-2.dll"
+    & dlltool.exe -d "$name-2.def" -D "..\..\bin\$name-2.dll" -l "lib$name.a"
+    del "$name-2.def"
+}
+
+Function Create-ImportLib([string]$architecture)
+{
+    New-Item -ItemType "directory" -Path "lib\gcc"
+    New-Item -ItemType "directory" -Path "lib\msvc"
+    Move-Item -Path "lib\*.lib" -Destination "lib\msvc"
+
+    $patharch = If($architecture -eq "x64") { "64" } Else { "32" }
+    
+    $oldpath = $env:Path
+    $env:Path += ";C:\tools\mingw$patharch\bin\"
+    
+    Push-Location "lib\gcc"
+    Convert-DLL("csfml-graphics")
+    Convert-DLL("csfml-window")
+    Convert-DLL("csfml-audio")
+    Convert-DLL("csfml-network")
+    Convert-DLL("csfml-system")
+    Pop-Location
+
+    $env:Path = $oldpath
+}
+
+Create-ImportLib $architecture