Patch for: T28298
Patch for [#28298] Header/footer scroll resets itself upon many actions
Removes hack to completley reset headers regions in ED_area_initialize().
Adds check to adjust "cur" variable correctly when "align" is using V2D_ALIGN_NO_NEG_Y.
Changes UI_view2d_totRect_set function in the header drawing code to use "headery" variable.
If more info on the bug or why this patch works is needed, I can explain in detail.