Make sure all arrays preserve 'depth' when calculating mip dims
Don't call into real glFlushMappedBuffer unless it was really mapped
Replay glTexBuffer commands in-frame
Propagate resource dirtiness over copies
Make sure bind-to-create chunks don't affect object state

* e.g. if the 'wrong' VAO was bound at the time we replayed a
  bind-to-create chunk, then we'd trample that VAO state (and it might not
  ever be restored). So when reading, not executing, save and restore the
  buffer binding.
Return some WGL extensions that we can easily support.
When replaying don't use VertexAttribPointer functions (or DSA equiv)

* It seems like there's some buggy behaviour when mixing and matching 'old'
  style vertex attrib pointer/offset functions, and the new attrib/vertex
  buffer binding style (which we use in VAO initial state since it's a
  superset of functionality).
* Fortunately, the spec defines exactly how VertexAttribPointer is defined
  in terms of the new system, so just do the replacement ourselves.
Fix enums being wrong when added to even tlist
Make sure last draw data is set every time, not just when reading

* These values are used to show the current pipeline state (as it's
  convenient to show this data with the rest of the 'state', even if it's
  not state. That means they need to be set every time when executing, not
  just once when reading.
Add fetching of Indirect params, and stepping through MultiDraw calls

* This means glMultiDrawIndirect is fetched, decomposed into child draw
  calls and you can step through them individually
Add a vendor check to avoid querying GL_POLYGON_MODE on AMD
Only query depth stencil texture mode for depth-stencil textures
Track if a context is core or not, re-check vendor checks on core

* When a compatibility context is created (via the old CreateContext, or
  via an appropriate CreateContextAttribs call), we can still do the vendor
  checks but we want to make sure we perform them again if we ever create a
  core profile context. Note that actually *using* a compatibility context
  isn't supported at the moment, but this won't explicitly break that.
Add vendor check to avoid glCopyImageSubData on <4x4 compressed mips
Add a vendor check to avoid glGetProgramPipelineiv+GL_COMPUTE_SHADER
Work around glVertexArrayVertexAttribDivisorEXT not being present