IVGCVSW-2454 Merge together the pluggable backends work (was in a
separate branch) and master

 * Brings in all the changes done for the pluggable backends
 * Added sub-graph support and tests
 * Added precompiled layer support and tests
 * Moved BackendSettings to a separate file
 * Removed the backend-specific code
 * Ported DebugLayer and associated functionality
 * Included fixes to make those changes work with master

Change-Id: Id7028fa7917527b844628d5aff5732e3d94c0488
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 616f616..b39f785 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -234,6 +234,8 @@
     src/armnn/layers/Pooling2dLayer.cpp
     src/armnn/layers/DivisionLayer.cpp
     src/armnn/layers/DivisionLayer.hpp
+    src/armnn/layers/PreCompiledLayer.hpp
+    src/armnn/layers/PreCompiledLayer.cpp
     src/armnn/layers/ReshapeLayer.hpp
     src/armnn/layers/ReshapeLayer.cpp
     src/armnn/layers/SpaceToBatchNdLayer.hpp
@@ -250,6 +252,7 @@
     src/armnn/layers/StridedSliceLayer.hpp
     src/armnn/layers/SubtractionLayer.cpp
     src/armnn/layers/SubtractionLayer.hpp
+    src/armnn/BackendSettings.hpp
     src/armnn/Descriptors.cpp
     src/armnn/DeviceSpec.hpp
     src/armnn/Exceptions.cpp
@@ -259,6 +262,7 @@
     src/armnn/Instrument.hpp
     src/armnn/InternalTypes.cpp
     src/armnn/InternalTypes.hpp
+    src/armnn/ISubGraphConverter.hpp
     src/armnn/JsonPrinter.cpp
     src/armnn/JsonPrinter.hpp
     src/armnn/Layer.cpp