!!! [FEATURE] Major version, first release

Several (breaking) changes are introduced in this first public
version.

* Moved TYPO3_ENVIRONMENT to TYPO3_CONTEXT
  can now be used with 4.5-6.2
* CONTEXT behaves now like the newly introduced functionality
  in 6.2
* CONTEXT can now be set via command line
* Mails can be intercepted and redirected to development email
  address, via SwiftMailer plugin