Originally intended to fix a bug in edit openning fils with non-ascii
characters.
Now all data is assumed to be manipulated as unicode. Therefore all
values returned by functions from content are unicode. There are a few
exception in order to download non-unicode data without failing to
decode. These exception are marked by the 'byte_' prefix.
The io package is used instead of builtin open for all file
transactions.
The fake_env test helper has to be modified (hacked, to be honnest) since
fake_filesystem does not offer a mock of io.
This is still WIP. Two issues still have to be solved:
- first there is an UnicodeWarning raised by bibparser,
- also config is still directly using builtin open.
* only bibtex format is supported
* all tests except test_repo.py and edit test pass
* edit and update commands were not updated
* removed --format argument from export, only bibtex is supported.
