all: Make compile with changes perform in VW
core: isisio: sessions: Rework headers

Attempting to enforce include what you use, forward declaring when
possible, and include order:

1. VW/ASP
2. System
3. All else
tools: Fix compilation issues due to missing headers
docs: Add back Zack's email address
.vwrc log example: clarify
Docs: Many clarifications and fixes for consistency

docs: Many clarifiations and fixes for consistency
docs: Expand DG tutorial, other refactoring

docs: Expand DG tutorial, other refactoring