small fix to makefile, removal of vim swapfiles

Here are a couple of minor patches.  The .*.swp files are left when vi (or vim) is killed.  They make editing the files annoying, as it pops up a recovery message instead of pulling the file up.  Also, since the object files are in the lib directory, make clean wasn't removing them.  The replacement line calls make clean in the lib directory, properly removing the object files (and their static library).