[AL_USDMaya] ProxyDrawOverride/ProxyShapeSelect removal

[fabal]

Hi there,
as we are working towards replacing AL_USDMaya with maya-usd in Animal Logic's pipeline and considering the size of our development team, we've decided to be more aggressive about the code base we support. The first "victims" are:

• the proxy draw override display (replaced a long time ago by the VP2 proxy render delegate)
• the AL_usdmaya_ProxyShapeSelect command (superseded by UFE selection)
  We're hoping that this decision won't affect anyone but let us know if that's the case.

[kxl-adsk]

Definitely, something we (at Autodesk) are supporting.