Holds utility functions that are general conveniences.
| now_string() | returns a unique sortable string, representing the current time |
| find_nearest(array, value) | find nearest value in array. |
| find_nearest_index(array, value) | find nearest value in array. |
| get_fid(file, *args, **kwargs) | Returns a file object, given a filename or file object |
| get_extn(filename) | Get the extension from a filename. |