Significant documentation fixes (#3364)

* Added VariableState to Plugin API documentation

* More fixes for plugin documentation

* Added ie_memory_state.hpp to documentation

* Added proper dependencies between C++ and Plugin API targets

* Fixed issues in public C++ API reference

* Fixed issues in public C++ API reference: part 2

* Removed obsolete entries from EXCLUDE_SYMBOLS in doxygen config

* Fixed path to examples, tag files for Plugin API doxygen file

* Put impl to a private section for VariableStatebase

* Fixed examples path to Plugin API: part 2

* Fixed path to examples in main ie_docs doxygen file

* Replaced path to snippets; otherwise path depends on how cloned repo is named

* Added path to snippets for ie_docs doxygen file as well

* Great amount of fixes for documentation

* Removed IE_SET_METRIC

* Fixes for C API documentation

* More fixes for documentation

* Restored Transformations API as a part of Plugin API

* Fixed tag files usage for Plugin API

* Fixed link to FakeQuantize operation

inference-engine/include/cpp/ie_cnn_network.h

@@ -124,7 +124,6 @@ public:
      * Wraps ICNNNetwork::setBatchSize
      *
      * @param size Size of batch to set
-     * @return Status code of the operation
      */
     virtual void setBatchSize(const size_t size) {
         CALL_STATUS_FNC(setBatchSize, size);

inference-engine/include/cpp/ie_infer_request.hpp

@@ -83,7 +83,7 @@ public:
     /**
      * constructs InferRequest from the initialized shared_pointer
      * @param request Initialized shared pointer to IInferRequest interface
-     * @param plg Plugin to use. This is required to ensure that InferRequest can work properly even if plugin object is destroyed.
+     * @param splg Plugin to use. This is required to ensure that InferRequest can work properly even if plugin object is destroyed.
      */
     explicit InferRequest(IInferRequest::Ptr request,
                           InferenceEngine::details::SharedObjectLoader::Ptr splg = {}):

inference-engine/include/cpp/ie_memory_state.hpp

@@ -3,7 +3,9 @@
 //
 
 /**
- * @file
+ * @brief A header file that provides wrapper classes for IVariableState
+ *
+ * @file ie_memory_state.hpp
  */
 
 #pragma once
@@ -25,8 +27,9 @@ class VariableState {
 
 public:
     /**
-     * constructs VariableState from the initialized shared_pointer
+     * @brief constructs VariableState from the initialized shared_pointer
      * @param pState Initialized shared pointer
+     * @param plg Optional: Plugin to use. This is required to ensure that VariableState can work properly even if plugin object is destroyed.
      */
     explicit VariableState(IVariableState::Ptr pState, details::SharedObjectLoader::Ptr plg = {}) : actual(pState), plugin(plg) {
         if (actual == nullptr) {
@@ -59,7 +62,7 @@ public:
      * @copybrief IVariableState::GetState
      *
      * Wraps IVariableState::GetState
-     * @return A blob representing a last state 
+     * @return A blob representing a state 
      */
     Blob::CPtr GetState() const {
         Blob::CPtr stateBlob;
@@ -67,7 +70,14 @@ public:
         return stateBlob;
     }
 
-    INFERENCE_ENGINE_DEPRECATED("Use GetState function instead")
+    /**
+     * @copybrief IVariableState::GetLastState
+     * @deprecated Use IVariableState::SetState instead
+     *
+     * Wraps IVariableState::GetLastState
+     * @return A blob representing a last state 
+     */
+    INFERENCE_ENGINE_DEPRECATED("Use VariableState::GetState function instead")
     Blob::CPtr GetLastState() const {
         return GetState();
     }
@@ -83,8 +93,9 @@ public:
     }
 };
 
-/*
+/**
  * @brief For compatibility reasons.
  */
 using MemoryState = VariableState;
+
 }  // namespace InferenceEngine