buffer writers feature

Hi, the following is my addition of buffer writers to your project. I am both new to elisp, and collaborating on github in this way. I've tested the writer functionality by use, but I've yet to do test-cases (since they are so small). If you want those then I may be able to produce them in a few weeks, and I would want to overhaul your test harnesses while doing so. I'm pretty exhausted and disgusted at this for now.