Commit 613f097

* allowed arrays to have metadata (e.g. title, description, authors, ...).

Metadata can be accessed using the syntax ``array.meta.name``.

See bellow for use cases:

>>> # add metadata to/from an array

>>> # for Python <= 3.5

>>> arr = ndtest((3, 3), meta=[('title', 'array for testing'), ('author', 'John Smith')])

>>> # for Python >= 3.6

>>> arr = ndtest((3, 3), meta=Metadata(title='array for testing', author='John Smith'))

>>> # access an item

>>> arr.meta.author

'John Smith'

>>> # update/add an item (the item is added if not found in existing metadata)

>>> arr.meta.city = 'London'

>>> # delete an item

>>> del arr.meta.city

Warnings:

- Currently, only the HDF (.h5) file format supports saving and loading metadata.

- Metadata are not kept when actions or methods are applied on a array

except for operations modifying the object in-place, such as `pop[age < 10] = 0`,

and when the method `copy()` is called. Do not add metadata to an array if you know

you will apply actions or methods on it before dumping it.

Closes :issue:`78` and :issue:`79`.

* deprecated attribute `title` of array objects. A title is now considered as a metadata

and must be added as:

>>> # add title at array creation

>>> arr = ndtest((3, 3), meta=[('title', 'array for testing')])

>>> # or after array creation

>>> arr = ndtest((3, 3))

>>> arr.meta.title = 'array for testing'

from larray.core.metadata import *