Improved some features

1. Use the correct unit for micronutrients like microgram or IU for vit A, vit D,... that will help users track food or create new food more easily.
2. Add suggested upper intake for nutrients base on gender, age, activity level so that users can manage what to eat.
3. In creating new food section, there should be more standard serving size than just 100mg or 100ml. In some countries like Vietnam, nutrition fact label shows serving size more variety like 30g, 50g, 180ml... So sometimes it will be inconvenient and inflexible. I love the old version of this feature that allows user to custom their standard serving size.
4. Also in creating new food, there has limited serving size for each type of food. It will be better if allows user to custom serving size such as a large, medium, small fruit; a large, medium, small package; an unknown size egg,
5. I wish this app can connect to more activity tracking apps or devices like zepplife (mifit), miband, miwatch,...