Remove those pesky environment variables. Closes #3817
Fixing warnings in solid mechanics module.

@backmari, can you comment on why you compute all these values but
they aren't used for anything?

Refs #1777.
Merge pull request #3819 from milljm/updateStable_env

Remove those pesky environment variables
Merge commit 'bacdfcf9848e732f78dd775a361d249c0f781111'
Merge pull request #3820 from jwpeterson/fix_warnings

Fixing warnings in solid mechanics module.
Merge commit '27ac890d617d027c50c04ea02db4bea91dffa018'