Added <string> header.

refs #7284
Added <string> header

refs #7284
Added <string> header.

refs #7284
Use method to check for successful file creation instead on NULL.

Don’t check for the file handle to be NULL, instead use the
is_open() method.
refs #7284
Find the G3d and GeomBase libraries.  refs #7284
Merge branch 'feature/7284_framework_clang' into develop