ACalc: fixed bug in tan function.
ACalc: fixed bug in tan function.

foam-framework/foam,jlhughes/foam,jlhughes/foam,jlhughes/foam,jacksonic/foam,jacksonic/foam,foam-framework/foam,jacksonic/foam,mdittmer/foam,mdittmer/foam,mdittmer/foam,foam-framework/foam,mdittmer/foam,jlhughes/foam,jacksonic/foam,foam-framework/foam,foam-framework/foam