Missing precedence rules for And and Or

The code generation in FFC does not consider precedence of the &&/|| operators vs <,>,etc., which may result in wrong results as seen in this case. Suggested fix is to always add () around arguments to && and ||, but I'm not sure I understand how the formatting rules work (strings vs. lambdas in the formatting dict).

from dolfin import *
mesh = UnitSquare(100,100)
x = mesh.ufl_cell().x

f = conditional(Or(And(lt(x[0], 0.5), gt(x[1], 0.3)), lt(x[1], 0.7)), 1, 0)
g = conditional(And(lt(x[0], 0.5), Or(gt(x[1], 0.3), lt(x[1], 0.7))), 1, 0)

fp = project(f, mesh=mesh)
gp = project(g, mesh=mesh)

print fp.vector().norm('l2')
print gp.vector().norm('l2')

plot(fp) # Wrong, looks just like g
plot(gp) # Correct

interactive()