Added support for form validations.

core/core.pro

@@ -15,7 +15,8 @@ SOURCES += \
     data/user.cpp \
     context.cpp \
     imetadataplugin.cpp \
-    transaction.cpp
+    transaction.cpp \
+    emptystringvalidator.cpp
 
 HEADERS += core.h\
         core_global.h \
@@ -26,7 +27,9 @@ HEADERS += core.h\
     imetadataplugin.h \
     autotablemodel.h \
     autoform.h \
-    transaction.h
+    transaction.h \
+    ivalidator.h \
+    emptystringvalidator.h
 
 unix {
     target.path = /usr/lib