Update lib/classes/Swift/MemorySpool.php
Implemented Swift_Message cloning + test
corrected typo
Cloning fixed
Added Message-Id regeneration
allow to set array of recipients in RedirectingPlugin
add GMail XOAuth2 support
Update plugins.rst

fix grammatical bug
NullTransport should report that all emails have been delivered.
UPDATE: extended mime_types.php with autogenerated and sorted extensions
 using following public sources:
 > http://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types
 > https://raw.github.com/minad/mimemagic/master/script/freedesktop.org.xml
UPDATE: autogeneration php script for mime_types.php;
changed code formatting and moved autogenerate script to lib
git apply cs.diff (code reformat)
Added NTLM authentication
Fixes issue that prevents the autoloader from working when unit tests are executed in separate processes with "@preserveGlobalState" enabled
Travis tweaks
Whitespace fixes
bumped version to 5.1.0-DEV
made some modification to previous merge
updated CHANGELOG