Added Column dialog for selecting visible columns. Selection is stored to settings.

core/core.pro

@@ -27,7 +27,8 @@ SOURCES += \
     users/users.cpp \
     users/usersui.cpp \
     users/tablemodel.cpp \
-    users/userform.cpp
+    users/userform.cpp \
+    columndialog.cpp
 
 HEADERS += core.h\
         core_global.h \
@@ -54,7 +55,8 @@ HEADERS += core.h\
     users/users.h \
     users/usersui.h \
     users/tablemodel.h \
-    users/userform.h
+    users/userform.h \
+    columndialog.h
 
 unix {
     target.path = /usr/lib
@@ -81,7 +83,8 @@ DISTFILES += \
 FORMS += \
     gridform.ui \
     formdialog.ui \
-    users/userform.ui
+    users/userform.ui \
+    columndialog.ui
 
 OTHER_FILES += \
     users/metaData.json