Merge pull request #1 from fsuter/master

[FEATURE] Allow nested values for crawler

The values passed to the crawler for adding to the POST request
can only be simple values. This patch makes it possible to pass
arrays to \TYPO3\CMS\Messenger\Utility\Crawler::addPostVar()
this making it possible to have more complex marker structures
in the messages (e.g Fluid markers such as {user.foo.bar}.
[TASK] Raise TYPO3 CMS dependency
[TASK] Adjust labels
[TASK] Update README file
[TASK] Update vendor name in namespace to be Vanilla\Messenger
[TASK] Use class alias and rename validator to be EmailValidator
[TASK] Convert class alias
[TASK] Rename class to become ObjectUtility
[FEATURE] Add "to", "cc" and "bcc"

The patch also deprecate the "recipients" property.
[FEATURE] Improve implementation of Crawler
[FEATURE] Better implementation of method Message->toArray
[FEATURE] Add generic show widget for representing an object
[FEATURE] Add run time storage of email body to be possibily used later in some view
[TASK] Update title and description in ext_emconf
[TASK] Add basic composer file
[TASK] Update README file
[TASK] Rename field "speaking_identifier" to be "qualifier"
[TASK] Remove closing PHP tag
[FEATURE] Add new message type
[TASK] Refactor label files