Refactoring resizing into state machine.

- Fixes MSTSC resizing (with RFX as well).
- Queue system so that resizes are processed when XRDP and the X server
are ready, not immediately.
- Deletes and recreates the encoder (RFX fix)
- Introduces a dynamic_monitor_description struct that is used for the
queue system.

xrdp/xrdp.h

@@ -397,18 +397,38 @@ xrdp_bitmap_compress(char *in_data, int width, int height,
 
 /* xrdp_mm.c */
 
-struct dynamic_monitor_layout
+enum display_resize_state
 {
-    int flags;
-    int left;
-    int top;
-    int width;
-    int height;
-    int physical_width;
-    int physical_height;
-    int orientation;
-    int desktop_scale_factor;
-    int device_scale_factor;
+    WMRZ_QUEUED = 0,
+    WMRZ_ENCODER_DELETE,
+    WMRZ_SERVER_MONITOR_RESIZE,
+    WMRZ_SERVER_VERSION_MESSAGE,
+    WMRZ_XRDP_CORE_RESIZE,
+    WMRZ_ENCODER_CREATE,
+    WMRZ_SERVER_INVALIDATE,
+    WMRZ_COMPLETE,
+    WMRZ_ERROR
+};
+
+#define XRDP_DISPLAY_RESIZE_STATE_TO_STR(status) \
+    ((status) == WMRZ_QUEUED ? "QUEUED" : \
+     (status) == WMRZ_ENCODER_DELETE ? "WMRZ_ENCODER_DELETE" : \
+     (status) == WMRZ_SERVER_MONITOR_RESIZE ? "SERVER_MONITOR_RESIZE" : \
+     (status) == WMRZ_SERVER_VERSION_MESSAGE ? "SERVER_VERSION_MESSAGE" : \
+     (status) == WMRZ_XRDP_CORE_RESIZE ? "XRDP_CORE_RESIZE" : \
+     (status) == WMRZ_ENCODER_CREATE ? "WMRZ_ENCODER_CREATE" : \
+     (status) == WMRZ_SERVER_INVALIDATE ? "SERVER_INVALIDATE" : \
+     (status) == WMRZ_COMPLETE ? "COMPLETE" : \
+     (status) == WMRZ_ERROR ? "ERROR" : \
+     "unknown" \
+    )
+
+struct dynamic_monitor_description
+{
+    struct display_size_description description;
+    enum display_resize_state state;
+    int last_state_update_timestamp;
+    int start_time;
 };
 
 int