DXR alpha 3 release

I am pleased to announce the third release of DXR. Compared to the previous release, the UI has been tweaked and several bugs have been noticed and fixed. In particular, I have improved the support of links, and fixed the bug that prevented the type hierarchy from being properly realized. I have also introduced support for indexing the IDL code in Mozilla's codebase, as well as indexing generated code in general. I have also added yet another tree, comm-central.

Compared to the original implementation of DXR by Dave Humphrey, there remains one unimplemented feature, namely support for the callgraph. My plan for the next release will focus on implementing this feature as well as any other bugs I uncover via real-world testing. The other major features for the next release will be a JSON query API for data and improved support for multiple trees.

In a more general viewpoint, the plugin architecture has been much improved. There is now support for viewing code-coverage data in the source tree (I do not have a visible demo of this yet), and the support for IDL is entirely a separate plugin. Implementing these plugins has caused me to realize that there is need for better hooks in the current architecture (especially with regards to the generated HTML), and these will also be forthcoming in the next release.

The final point to make is that I have moved the viewsource code into its own repository, as well as adding support for a limited subset of the clang AST. The website does not properly support clang at this time owing to problems in the server's current toolchain configuration; when these issues are resolved, I will be demonstating the tool better.