Complete fix for libreoffice datetime field

See #3 for reasons.

Bug fix: date field could have datetime from libreoffice

see more details in #3

bug fix: utf-8 string throw unicode exceptions

See more details in #2 and pyexcel/pyexcel#12

Quick release to get rid of buggy odfpy 1.3.0

but stay with odfpy 0.9.6

Bug fix: "number-columns-repeated" is now respected

As in subject

Unified api acorss pyexcel-* extensions

• get_data and save_data are seen across pyexcel-* extensions. remember them once and use them across all extensions.

Optimization for loading single sheet from a multiple book

• Loads only one sheet from a multiple sheet book
• Use New BSD License

IO interface update

• IO interface update as pyexcel-io introduced keywords.

initial release

• read, manipulate and write data in ods format
• use pyexcel-io interface