add ability to find elements that are intersected by a line refs #4345
Removed extra newlines and print statement (refs #4343)
Created INL specific slideset objects to reduce input file syntax (refs #4343)
Merge pull request #4346 from friedmud/elems_along_line_4345

add ability to find elements that are intersected by a line
Merge pull request #4351 from aeslaughter/training-4343

Improvements to PresentationBuilder to reduce input file syntax