added examples for other nuclear data libraries, changed all to 300 K
Fix typo in user's manual for 'separate' attribute of source_point.
delete example inputs for all data libraries except those from nndc
Changed fox URL to a public URL
Merge pull request #283 from walshjon/other-library-examples

added examples for other nuclear data libraries, changed all to 300 K
Merge pull request #284 from smharper/fox_public_URL

Changed fox URL to a public URL
Expand description in two error messages that seem to be encountered most often
among new users.