* Mostly moving includes from common headers to cpp where possible, and removing
includes of the whole thing where only enums or rdcstr etc are needed.
* Instead of just configuring SPIR-V disassemblers and picking only the first
one when we need to edit SPIR-V, we allow setting up any shader processor that
goes between two shader encodings.
* When editing, the default will still be to use embedded source, and then after
that the first tool that goes from the native shader format to a text format,
but the drop-down allows you to pick any of them.
* Similarly in the shader viewer you can configure the compilation options and
method, to choose the compiler you want to use. Embedded command line
parameters in the shader are automatically appended.