Bug issue #1943 - First check if parameter $param['Action'] is setted

Bug issue #1943 - First check if parameter $param['Action'] is setted
Rename function my_save_extra_profile_fields to mailjet_my_save_extra_profile_fields - RedMine issue #2110

Rename function my_save_extra_profile_fields to
mailjet_my_save_extra_profile_fields - RedMine issue #2110
README.md update

Update the changelog about - Rename function
my_save_extra_profile_fields to mailjet_my_save_extra_profile_fields
RedMine issue #1553

We display more human readable messages for those cases when we enter
wrong API/Secret Key and also our "from email" does not match with any
of the sender part of our Mailjet's account
RedMine issue #1553 - fixing bug

The senders were not extracted correctly
Merge pull request #21 from mailjet/development

Merge the development and master branches