use_displaced_mesh = false in all Mesh blocks for linear elastic coupling

[mangerij]

displacements=’disp_x disp_y disp_z’ in GlobalParams activates the displaced mesh in the Mesh block by default. This is problematic because it creates needless overhead while we are working with small strains (the linear elastic limit).

Tests should reflect this so users don't get confused and all calculations can run a little faster. May require re-golding.

[mangerij]

This is a possible issue to scaling but also not origin of current bug being investigated (see moose-users list for week of june 1 ).

Note when used_displaced_mesh = false is used in the Mesh block, the PBC problems give incorrect solutions (no longer get correct domain wall boundary orientations w.r.t crystallographic symmetry)