#1024 Removed attribute access by reference in Variable
#1024 Removed binding equations from Variable
#1024 Refactored SymbolicOCP::addVariable
#1024 Removed SymbolicOCP::find
#1024 Added support for obtaining attributes given expressions in SymbolicOCP
#1024 Added nominal parameter to SymbolicOCP attribute retrieval
#1024 Removed attribute retrieval by variable vector
#1024 Removed SymbolicOCP::variableByType
#1024 Changed SymbolicOCP::z type to SX
#1024 Changed SymbolicOCP::y type to SX
#1024 Changed SymbolicOCP::u type to SX
#1024 Changed SymbolicOCP::q type to SX
#1024 Removed der(vector<Variable>)
#1024 Changed SymbolicOCP::pf type to SX
#1024 Changed SymbolicOCP::pi type to SX
#1024 Changed SymbolicOCP::pd type to SX
#1024 Changed SymbolicOCP::ci, SymbolicOCP::cd type to SX
#1024 Changed SymbolicOCP::x type to SX
#1024 Changed SymbolicOCP::s type to SX
#1024 Updated variable names in SymbolicOCP