Cleaned up renderdoccmd, split out necessary bits to OS-specific files
Fixes for compiling on linux
Commit latest mhook changes from https://github.com/martona/mhook
Handle case where UpdateSubresource is recorded for unused resource

* If a resource isn't referenced anywhere else (ie. isn't then serialised
  out to the logfile by default and has no live resource equivalent) we
  need to account for this and simply skip the UpdateSubresource. Similar
  things are done for CopyResource etc
* This is backwards compatible with old logs as it handles their case with
  a "missing" resource
Don't try and hook OpenGL functions if the dll isn't even loaded on win32
Don't bake DrawcallTreeNodes too early, just copy children across.

* Fixes markers within deferred contexts from not showing their children
  in the event browser (although they would still replay the events)
Add a macro (that is default on) to include win8 sdk dependency

* Disabling the macro means that the DirectX SDK (June 2010) should be the
  only dependency and you can compile as normal, just without d3d11.1
  support.
* This won't be massively supported and official releases will not use this
* It might break in future as I won't be testing, it might even be deleted
  to tidy up, but until then it might come in handy for some.
Handle exceptions when saving config files and alert the user
Protect against crash report exception, check rect is valid size
Actually serialise out IDs for texture bindings instead of empty array.
Hook a couple more GL debug message functions
Add single depth range functions, change renderstate to fetch by index
Add support for EXT_depth_bounds_test
Add other BaseVertex variants of glDrawElements*, and glDrawRangeElements
Support Push/Pop markers from KHR_debug and implement begin/set/end
Compile error fixes
Demote some hook errors as they don't seem to succeed on win64 currently
After each command list execute, renumber child draws. Closes #62
Add functions for separable programs and program pipelines.
Implement glDetachShader (might not behave correctly, need to test)