Solution part of computeG moved to BeamModel
Almost there, need to fix no crack opening behaviour!
Functioning

Moved BeamModel constructor in to speed loop
Not technically correct
Constructor replaced
Reference to computeG removed
Needs reverting
Revert "Needs reverting"

This reverts commit 5ff79309575f9877ef16bf9b51a2627fde915de5.
Header cleanup
Merge branch 'V2.75'