Eml-parser

Fixed
- Fix routing.parserouting() to handle domains containing the word 'from' by themselves (thanks jgru 51).

Changed
Adapted the *examples/simple_test.py* to use the eml_parser class instead of the deprecated method.

Fixed
- When parsing URLs from the body:
- do not try to replace "hxxp" by "http" as we do not parse "hxxp" anyway (legacy)
- skip URLs with no "."
- update the regex for searching for URLs based on https://gist.github.com/gruber/8891611 in order to prevent infinite runs in certain cases (thanks kevin-dunas)

Fixed
Implemented a workaround for an upstream bug (https://bugs.python.org/issue30681) which breaks EML parsing if the source EML contains an unparsable date-time field (thanks nth-attempt).

Fixed
Fixed a bug which prevented correct attachment parsing in certain situations (thanks ninoseki).

Changed
Use simple less time consuming regular expression for searching for IPv4 addresses, in turn use *ipaddress* for both IPv4 and IPv6 address validation which is fast and gives in turn leads to more correct matches.

Added
- Simplify the code by using a sliding window body slicing method

Changed
- Use alternative URL extraction regular-expression
- Fix other regular-expressions (non-required escaping and ^)
- No longer support parsing h**xx**p(s) style URLs

Fixed
- In some cases the extracted features (i.e. domain, IP, URL, e-mail) were not correct due to wrongfully cutting through the body. This has been fixed by extending the text slice to a character unrelated to the match pattern.