optimize includes in some files

alib2data/src/alphabet/Symbol.cpp

@@ -7,7 +7,6 @@
 #include "Symbol.h"
 #include "LabeledSymbol.h"
-#include <core/xmlApi.hpp>
 #include "label/Label.h"
 namespace alphabet {

alib2data/src/label/Label.cpp

@@ -8,7 +8,6 @@
 #include "Label.h"
 #include "PrimitiveLabel.h"
 #include <primitive/Primitive.h>
-#include <core/xmlApi.hpp>
 #include <object/Object.h>
 #include "ObjectLabel.h"
 #include <alphabet/Symbol.h>

alib2data/src/regexp/RegExp.cpp

@@ -14,7 +14,6 @@
 #include "unbounded/UnboundedRegExp.h"
 #include "unbounded/UnboundedRegExpStructure.h"
-#include <core/xmlApi.hpp>
 namespace regexp {

alib2data/src/regexp/RegExp.h

@@ -15,7 +15,6 @@
 #include <string/StringFeatures.h>
 #include <string>
 #include <vector>
-#include <set>
 namespace regexp {

alib2data/src/string/String.cpp

@@ -9,7 +9,6 @@
 #include "LinearString.h"
 #include "CyclicString.h"
 #include "Epsilon.h"
-#include <core/xmlApi.hpp>
 namespace string {