When drawing viewport strings, the StringID is used to determine how to draw the sign. Instead, allow the behaviour to be set by the caller with flags. This means that some of the viewport-specific strings are no longer necessary.
ViewportAddString() now returns a pointer to a string as it may not actually add the string, in which case preparing the string parameters in advance is a waste of time.
Small viewport signs are drawn with FS_SMALL, so there is no need to duplicate text effect strings for both normal and small versions.
This also avoids an extra string format when text effect positions are updated.
House picker is accessed from the Landscaping toolbar as there is no town toolbar.
Once placed these houses behave like any other and can be removed by players and towns.
Uses the unified picker system, so also supports used/saved favourites. As town building don't have class labels, town zones are use to imitate them.
This allows ctrl-click on a type in a build-picker window to remember it
as a favourite. An new filter button to show only favourites makes it
simpler to use these types.
Favourite types are saved locally in favs.cfg, so are remembered between
games.
This filters the build-picker type lists to only show types that have
already been placed in the current game, making it simpler to get to
build matching features.
Toggling the "All" filter causes the class selection to be ignored, so
that items from all classes can be displayed together. The class text
filter is still applied.
This makes it easier to search amongst types for a feature.
These windows now share a common code base for choosing and display class and types.
An additional text filter is added to search types by name instead of just classes.
Slider widgets can only use a predefined list of values and strings to draw labels. This makes it difficult to vary the display by context.
Instead of providing a predefined list as a std::map, use a callback function instead. This function can decide what text to display, and can call SetDParam to dynamically set up strings.
