[$] Kernel symbol namespacing

In order to actually do anything, a kernel module must gain access tofunctions and data structures in the rest of the kernel. Enabling andcontrolling that access is the job of the symbol-export mechanism. Whilethe enabling certainly happens, the control part is not quite so clear;many developers view the nearly 30,000 symbols in current kernels that areavailable to all modules as being far too many. The symbolnamespaces patch set from Martijn Coenen doesn't reduce that number,but it does provide a mechanism that might help to impose some order onexported symbols in general.