NEWS: prepare for 6.6.5
Engine/Task/ObservationZones: BGAStartSectorZone: Change from KeyholeZone to SymmetricSectorZone

A BGAStartSectorZone has no keyhole.
build/kobo.mk: Include italic font variants
Screen/*: Load "real" italic font variants if they exist
Merge branch 'master' of git://git.xcsoar.org/xcsoar/apf/xcsoar
RowFormWidget: AddButton() returns WndButton pointer
KoboMenu: change window title
LargeTextWidget: add DialogLook reference

Don't use UIGlobals.  This is a generic class that shouldn't use
UIGlobals.
RowFormWidget: split into several source files

Allow reducing link-time dependencies.  For example, allow KoboMenu to
be linked without the units library.
Form/Edit: remove obsolete code comment
DataField: use C++11 "override" and "final"
DataField/Integer: use "mutable" instead of "const_cast"
DataField/Time: rename "display_buffer" to "string_buffer"
DataField/Time: implement GetAsString()

Return a string that can be parsed later.
DataField/Enum: rename "mHelp" to "help"
DataField/Enum: implement move operator with std::swap()

Eliminate unnecessary duplicate memory deallocation.
DataField/Float, ...: add internal ParseString() functions
DataField: pass reference string to CreateComboList()

Prepare for eliminating the complicated save/restore code from
dlgComboPicker().  Don't modify a DataField's value until the user
really modified it.
Dialogs/ComboPicker: don't modify the DataField value for paging

Pass the reference string to CreateComboList().
DataField: remove unused attribute "detach_gui"