v0.18.0

• Adding FiniteStack.
• Adding #.keys to MultiSet.
• Adding #.count alias to MultiSet.
• Adding #.count alias to MultiMap.
• Adding #.remove to MultiMap.
• Adding Vector.from.
• Adding #.values to Vector.
• Adding #.entries to Vector.
• Fixing bug when feeding invalid values to a MultiSet.
• Fixing .from static methods not taking byte arrays into account.
• Fixing bugs related to Stack.pop edge cases.
• Optimizing Stack performance.