I added examples/data/getSEDs.py and examples/data/getLSSTBandpass.py, which download the source files from the most canonical sources I was able to find, and then truncate and thin them.  The output of these scripts (the examples/data/CWW* and examples/data/LSST_* files), are also included in the repo, of course, so users don't have to run these, but they're here in case they're curious.  I also updated the comment sections at the beginning of the files to point to their online sources.