Add a new function to determine if a geometry will be accepted by routines not handling curve geometries

[aaime]

ST_HasArc almost does the job, but will return "false" on a curve geometry that does not contain any circular segment (e.g., a compound curve that only contains straight segments).

Please add a new function to determine if a geometry is safe to use with "non curve aware" functions (regardless of its circular segment contents)

[strk]

could be done by only looking at GeometryType output (recursively checking within GEOMETRYCOLLECTION, which does allow for internal curves)

[pramsey]

The problem is not so much in categorizing whether a geometry has curves in them as in categorizing which functions do or do not handle curved geometries. It might be better just to do a run through the whole functional set and pushing all arc's through stroking so that we have no functions that do not "support" curved geometry. If that results in a little weirdness (the first stop in running simplify on an arced object would be adding a bunch of vertices to it) at least we'd have 100% functional coverage for those types.

[pramsey]

I think I'd rather move to more universally stroking all arc features and just feeding them through rather than trying to flag/error them.