Update acalc build.sh script to work on Mac OS X
Update acalc build.sh script to work on Mac OS X

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