Clean up magic numbers

[php1ic]

Not particle magic number (i.e. 2,8,20 etc)

There are a lot of magic numbers scattered throughout the code, mainly due to the formatting of the data files, e.g position of the mass-excess value in the NUBASE, or the header size for AME.

Look into either refactoring them into a single header (or enum?) or individually per file/mass database.

[php1ic]

This looks to be done.
There might be one or two hiding somewhere, but they can be removed as they are discovered.