(2.0) Update documentation

[deplinenoise]

Lots of new stuff to document, including:

• New frontend/backend split
• t2-inspect for debugging
• Improved VS2012 project generation (might make an example for that)

[leidegre]

Some things I've noticed so far, trying to upgrade from 1.0 to 2.0:

• make_node is no longer a member of env and you now have to require package tundra.depgraph where you previously would do env:make_node

local depgraph = require "tundra.depgraph" -- now call depgraph.make_node instead of env:make_node

• make_node now requires data parameter Env to be specified (it cannot be nil).

The parameter env (which should be available in the context where you would call make_node) must be propagated manually. You may modify it if you wish.

• load_toolset has been moved from tundra.boot to tundra.unitgen.

I'll try to add to this list as I uncover things, I might have gotten some of this wrong but this is what I've learned, so far.

[deplinenoise]

Maybe we should put all this + more in a "Migrating from Tundra 1.0" in the docs?

Other stuff I know has changed is the SupportedHosts attribute that controls what goes in the DAG.

[leidegre]

I agree, but do you mind accumulating some of that information here first? I'll happily write it up and submit a pull request later.

[lundmark]

I've noticed that using Glob or FGlob requires the "tundra.syntax.glob" require which isn't specified in the documentation. I can't seem to find any documentation about how to use the project generation at all. It would be awesome with some sort of documentation on the project generation since I really want to use it :)

[emoon]

Something that would be nice to document also is existing environment variables one can use like $(HOSTPROGSUFFIX) , $(SEP), $(OBJECTDIR), etc