Stabilizing a few things.

Music plays, httpd responds in a snap, messaging subsystem works, full
end-to-end flash erase/flash/configure wifi & hardware/reboot to
squeezelite was tested.

CMake system works well:  it now allows to flash in a single command
(assuming esp-idf V4.0 is properly installed on the system) with the
standard line:

idf.py flash -p <comport>

this makes building and flashing the app less confusing for new
developers/users wanting to experiment

components/display/CMakeLists.txt

@@ -2,7 +2,7 @@
 idf_component_register(SRC_DIRS . core core/ifaces  fonts
 						INCLUDE_DIRS . fonts core
 						REQUIRES platform_config tools esp_common
-						PRIV_REQUIRES services freertos    driver           
+						PRIV_REQUIRES services freertos driver           
 )
 
 set_source_files_properties(display.c

components/display/core/ifaces/default_if_i2c.c

@@ -15,6 +15,7 @@
 #include "gds_err.h"
 #include "gds_private.h"
 #include "gds_default_if.h"
+#include "messaging.h"
 
 static int I2CPortNumber;
 static int I2CWait;
@@ -89,6 +90,12 @@ bool GDS_I2CAttachDevice( struct GDS_Device* Device, int Width, int Height, int
 static bool I2CDefaultWriteBytes( int Address, bool IsCommand, const uint8_t* Data, size_t DataLength ) {
     i2c_cmd_handle_t* CommandHandle = NULL;
     static uint8_t ModeByte = 0;
+    static uint32_t failures=0;
+    if(failures > 1000){
+    	ESP_LOGE("I2C_Display","I2C Write failure");
+    	failures = 1;
+    	return false;
+    }
 
     NullCheck( Data, return false );
 
@@ -108,6 +115,10 @@ static bool I2CDefaultWriteBytes( int Address, bool IsCommand, const uint8_t* Da
     return true;
 	
 error:
+
+    if(++failures == 1){
+    	messaging_post_message(MESSAGING_ERROR,MESSAGING_CLASS_SYSTEM, "Display communication failed.");
+    }
 	if (CommandHandle) i2c_cmd_link_delete( CommandHandle );
 	return false;
 }