Support rectangle range query syntax for indexed shapes & worldBounds

Want to do a spatial query using the RPT field type using an arbitrary rectangle? There are two choices right now (and I'm omitting the deprecated 3rd choice):

• field:["minX minY" TO "maxX maxY"]
• field:"ENVELOPE(minX, maxX, maxY, minY)" (the Y order is not a typo)

But what about indexing a rectangle? Or configuring the worldBounds attribute on the field type? For both those (and again, omitting the deprecated choice), you just have ENVELOPE. Well... if you have JTS then you can also do a 4-point polygon.

What this issue proposes is that the rectangle range query syntax be parsed by Solr as a shape syntax for indexing & worldBounds. It'll add consistency, and it means you don't need to see/use WKT unless you have complex shapes. That way you never have to use WKT if you don't have complex shapes. (well, indexing a circle is still an exception)