Function object updates

Renamed the residuals function object to solverInfo since it now generates:

• residual fields
• solver type
• initial residual
• final residual
• number of solver iterations
• convergecnce flag

Added new continuityError function object. Example usage:

continuityError1
{
    type        continuityError;
    libs        ("libfieldFunctionObjects.so");
    ...
    writeToFile yes;
    log         yes;
    phi         phi;
}
\endverbatim