htmlparser: Fetch mboxes from FTP servers

FTP servers return a plain page that contains the list
of files on the directory. Each line has the next pattern

  -rw-r--r--  1  500  500  1799055  Sep 30  2013  mbox

where 'mbox' is the file name. This commit adds the code for
parsing those lines.

Fixes issue #33
htmlparser: Use urlparse to get URL scheme
htmlparser: Fix error sorting MBox links

Using sort() method caused that MBox files with format '%Y-%B'
(i.e 2014-May) were not analyzed from oldest to newest.
In Mailman, files (or links) are list from newest to oldest so
we needed to invert the order.
Use get_database instead of create database
dbn: Add new database module/definition using SqlAlchemy
dbn: Add session implementation to integrate the new database
dbn: Add class Report for generating reports from the database
Integration of SqlAlchemy classes in mlstats
ci: Update .travis.yml for continuous integration
dbn: Remove unused methods
Remove old database code
db: Move new database implementation in the old namespace

Last step to replace the old database implementation with
SqlAlchemy
db: Force convert to unicode for MySQL dialect
Simplify logging information
Remove admin parameters to the create database

Since SqlAlchemy, we will rely on the user to create the
database, though we will create the tables if they don't
exists. Therefore, this option does not makes sense anymore.
tests: Update tests according to latest changes in analyzer

We now returns a datetime instead of a ISO string, therefore,
the test should reflect that comparison
setup: Update meta data