Add a helper script to test MinGW builds locally (to help debugging the build server)

resources/mingw.bat

@@ -0,0 +1,15 @@
+@rem MinGW build test - used to test MinGW builds locally
+@rem Adapt path/versions before use
+
+@rem This batch file must be used from the repository root
+@if exist mingw.bat cd ..
+
+
+@set PATH=%ProgramFiles%\mingw-w64\i686-4.9.2-win32-dwarf-rt_v3-rev1\mingw32\bin;%PATH%
+@set PATH=%ProgramFiles%\GnuWin32\bin;%PATH%
+
+@rem Alternative ways to use mingw
+@rem make CC=gcc CFLAGS=-w CFLAGS+=-Iinclude/ CFLAGS+=-lws2_32 CFLAGS+=-liphlpapi
+@rem gcc src\civetweb.c src\main.c -Iinclude\ -lws2_32 -lpthread -lcomdlg32 -w
+
+make build CC=gcc WITH_LUA=1 WITH_WEBSOCKET=1