Fix for optimized clang 7 builds
When building current ALUGrid with clang 7 in optimized mode (-O3), I get assertion errors during grid construction. I traced the problem down to the utility function cyclicReorder(), which contains a rather complicated expression that lacks intermediate sequence points. This seems to horribly trip up clang's optimizer.
Fixed by splitting the offending expression into separate statements.
Closes #50 (closed)