Add __FreeBSD__ where needed to properly compile on FreeBSD + fix for Windows

src/util/GLExt.cpp

@@ -9,7 +9,7 @@
 #include <OpenGL/OpenGL.h>
 #endif
 
-#ifdef __linux__
+#if defined(__linux__) || defined(__FreeBSD__)
 #include <dlfcn.h>
 #endif
 
@@ -60,7 +60,7 @@ void initGLExtensions() {
     CGLSetParameter (CGLGetCurrentContext(), kCGLCPSwapInterval, &interval);
 #endif
 
-#ifdef __linux__
+#if defined(__linux__) || defined(__FreeBSD__)
     dlopen("libglx.so",RTLD_LAZY);
 
     void (*glxSwapIntervalEXTFunc) (Display *dpy, GLXDrawable drawable, int interval) = 0;

src/util/MouseTracker.cpp

@@ -30,7 +30,7 @@ void MouseTracker::OnMouseMoved(wxMouseEvent& event) {
 
     if (isMouseDown || isMouseRightDown) {
 #ifndef __APPLE__
-#ifndef __linux__
+#if !defined(__linux__) && !defined(__FreeBSD__)
         if (horizDragLock && vertDragLock) {
             target->WarpPointer(originMouseX * ClientSize.x, (1.0 - originMouseY) * ClientSize.y);
             mouseX = originMouseX;