Attributes review

My first contribution for this project that I use a lot! 
So to start small, I did only some very small changes that are very important to my use case of FileHelpers (public access to atributes information).

**List of changes:**

1. Change of all attributes field to properties with public get access and private set access. This will allow anyone to read the attribute settings if needed.
2. Added comments `<summary>`  to all public properties.
3. Minor refactoring of properties names to be coherent with its new public read access.