Merge pull request #448 from AlexandreToyer/master

Documentation: add page about selenium
Update geolocation.md
Update _prefix.md
Update how-to-use-selenium-to-crawl-websites.md
Update how_to_exclude_some_part_of_webpage_from_crawling.md
Update how_to_check_the_environment_variables_on_Windows.md
Update how_to_install_Tesseract-3_on_Debian.md
Update how_to_reset_forgotten_username_or_password.md
Update known_exceptions_and_error_messages.md
Update out_of_memory_issue.md
Update geolocation.md
Update how_to_allow_search_into_words.md
Documentation: renamed page