title: Search entire project for includes in Eclipse CDT
body: <p>I have a large existing c++ codebase.  Typically the users of the codebase edit the source with gvim, but we'd like to start using the nifty IDE features in Eclipse.  The codebase has an extensive directory hierarchy, but the source files use include directives without paths due to some voodoo we use in our build process.  When I link the source to my project in Eclipse, the indexer complains that it can't find any header files (because we don't specify paths in our includes.)  If I manually add the directories from the workspace to the include path then everything works wonderfully, but obviously adding hundreds of directories manually isn't feasible.  Would there be a simple method to tell Eclipse to look anywhere in the project for the include files without having to add them one by one?  If not, then can anyone suggest a good starting place, like what classes to extend, for writing a plugin to just scan the project at creation/modification and programatically add all directories to the include path?</p>