Add VC++ 9.0 `.sln` file (just for convenience).
Add "cJSON" source files (http://sourceforge.net/projects/cjson/), and note them in `makefile.msvc` and `vs/sumatrapdf-vc2008.vcproj`.
Adapt `src/BaseEngine.h` so that it keeps the doc's MD5 sum, and stores a JSON object. Add `src/BaseEngine.cpp` which reads the JSON ToC file.
Modify `src/PdfEngine.cpp` so that it creates "real" `PdfTocItem`s from the JSON object in `BaseEngine`.
Add `README.md` (Markdown) file, rename the original `readme.txt` file.