New column page

Shows SQL for columns ALTER TABLE ... [ADD|DROP] COLUMN combines a selection
of multiple columns into a single alter table.
Show collation in list of columns.

(order of columns isn't what is should be but that should maybe be fixed
by a generic column selection and ordering mechanism that knows what the
default sort should be)

pglab/pglab.pro

@@ -79,7 +79,8 @@ PropertyProxyModel.cpp \
     PropertiesPage.cpp \
     PasswordPromptDialog.cpp \
     ProcTableModel.cpp \
-    FunctionsPage.cpp
+    FunctionsPage.cpp \
+    ColumnPage.cpp
 
 HEADERS  += \
     QueryResultModel.h \
@@ -136,7 +137,8 @@ CustomDataRole.h \
     PropertiesPage.h \
     PasswordPromptDialog.h \
     ProcTableModel.h \
-    FunctionsPage.h
+    FunctionsPage.h \
+    ColumnPage.h
 
 FORMS    += mainwindow.ui \
 	ConnectionManagerWindow.ui \