* Added new generic "Location" class to handle 2D integer locations. Going to use it to replace all RegionHandle and X,Y coordinate references throughout the entire project. You have been warned.
* This patch addresses a regression where 5 default textures, including the default "new prim" texture, would not be shown unless in viewer cache.
* Further, it supplies a new plywood texture as the base texture, which is purpose-made from locally photo-sourced material (means i took a picture and made it into a tile), which is closer in appearance and color to the Linden one.
* It changes the default new prim texture UUID to match the UUID generated by the viewer when "default" is clicked, which is a texture UUID hardcoded in some scripts as well, so it would cause compatibility issues if not addressed.
* The patch fixes a number of UUID duplications (same UUID for asset and inventory items) and capitalization issues in the XML files.
* It also includes new versions of 4 other textures, which were no longer loadable in grid mode.
* PrimitiveBaseShape: The textures are now exposed as a 'TextureEntry Textures'; all serialization still using the 'byte[] TextureEntry' for backwards compatibility.
* Scene: Re-added AddTree, since the Tree type isn't gone from libsl, merely relocated.
