Revert "Removes annotate module, since its too dependant of CPython to be usable reliable in other projects"

This reverts commit 021241773d81fef606c81c75d5fd34f8030653cb.
Merge branch 'develop' into rescuing-annotate
Add absolute import for "fs".
Merge branch 'develop' of /media/med-ca/git/xoutil into develop
Delete "optparse" to use "argparse".
Start a project for detecting duplicate files.
Delete from repo "xoutil/optparse.py".
Merge branch 'develop' into med-develop
Fixes docstrings
Yet other PEP-8 fixes.
Starts integrate configuration manager.
Organize all modules related to options and configuration inner "xoutil.config".
Minor fix avoid "from string import *".
Reintroduces deprecation of normalize_to_str. It was wrongly removed when merging.
Creates `xoutil.string.names` to help writing __all__
Introduces `xoutil.compat.integer`. It will be long in Python 2 and int in Python 3.
Refactors decorators and mdeco. Creates the package `xoutil.decorator`.
Introduces a `followlinks` parameter in 'iter_files` and `iter_fict_files`.
Introduces functions `compose` and `pow_` in `xoutil.functools`.
Introduces function `up` in `xoutil.fs.path`.