Add more instructions to the Maya plugin Github instructions.
Bumping to Houdini Version: 13.0.386
Houdini Engine Version: 1.6 (API: 22)
Rename some files and class names

Mainly to remove redundant "Asset" word in many files, and add "Output"
for output related classes.
Remove spaces and extra blank lines
Add MIT license to Maya code
Convert tabs to spaces
Some more space fixes
Bumping to Houdini Version: 13.0.398
Houdini Engine Version: 1.6 (API: 22)
Compile the Maya plug-in on Mac OS X
Bumping to Houdini Version: 13.0.401
Houdini Engine Version: 1.7 (API: 13)
Move haveGeosChanged checks from OutputGeometry to OutputGeometryObject
In OutputGeomtry constructor, call update()

This avoids duplicate code for updating the HAPI_GeoInfo.
Add some macros for error checking
Make sure OutputGeometry::myParts is initialized even when HAPI_GetGeoInfo() failed

Even when HAPI_GetGeoInfo() failed, there's always at least one part. So
we want the below code to initialize myParts.
Remove some dead code
Bumping to Houdini Version: 13.0.402
Houdini Engine Version: 1.7 (API: 13)
In OutputGeomtryPart constructor, call update()

This avoids duplicate code for updating the HAPI_PartInfo.
Avoid creating the mesh node if the part doesn't contain a mesh.

The mesh node is also grouped under its own transform. This is more
consistent with other output types.
Create the grid data with MFnFloatArrayData directly

This avoids an extra copy of the grid data.
In OutputGeometryPart::createVolume, use std::vector to store the tile data