ButtonRenderer.cpp: make rounded buttons apply to OPENGL only

GDI uses an OS button sometimes
Screen/Util.cpp: refactor - consolidate Fancy button code

Add DrawButtonFancy, which is called by both Canvas.cpp and
by ButtonRenderer.cpp for OPENGL
XCSoar.cpp: fix log text bug

was repeating "based on based on" in "starting top hat" message.
InfoBoxes/Panel/GRAverage.cpp: fix for GDI compilation

(for PC, PPC2003 etc) it was not compiling
Screen/Util.cpp: use DrawRoundRectangle

Instead of manually creating this shape
Zoom, MainMenuButtons: don't draw square

Let the ButtonRenderer draw the outline.
This makes it thinner which may be too thin.  Have not tested this
with users
GlueMapWindowEvents.cpp: allow really short taps on map to clear menu

Don't require any length of "tap time" for a click for it
to trigger clearing of an active menu.
InfoBoxes/Content/Task.cpp: show "Not Configured" in Home IBs

Instead of showing "---" if Home IBs are not configured, it now says
"NA" and "Not configured"
InfoBoxes/Content/Task.cpp: HomeAltReq: show Home Dist in comment
InfoBoxes/Content/Glide.cpp: GRCruise.  Show Cruise dist in comment
InfoBoxes/Content/Factory.cpp: spell out Glide Ratio instead of GR

In long description, spell it out.
NEWS.txt: update
InfoBoxes/Content/Factory.cpp rename "Home altitude required"

Corrected name is "Home altitude difference"
InfoBoxes/Units.cpp: use distance units (not "small" units)

When displaying values for distance.  Use 1 decimal and main distance
unit.  Don't use "DistanceSmart" routine.
TaskNavSliderShape.cpp: use 1 decimal place in distance.

Don't use "DistanceSmart" which uses feet instead of miles etc
for small distances.  That confuses the user, especially on startup
because "0.0 feet" implies altitude, not distance.
TaskManager: remove Mat "auto add turnpoint" behaviour

When flying a Mat, we now require that the pilot click on each
point to add it.  The prior behaviour added the point automatically
when a pilot flew over it.  This tested as confusing and created
potentially incorrect statistics if the task has mandatory
turnpoints.