refs #6564 refactored out HtmlMessageException and introduced some other exceptions instead
refs #6577 Return HTTP 204 instead of GIF for JavaScript tracking.

added a new url parameter send_image=0 to disable sending an
image and instead response with a 204 code
refs #6577 updated changelog
use HTTP 1.1
refs #6665 fix missing translation key in websites management
language update  refs #3430
Merge pull request #6668 from piwik/translationupdates

[automatic translation update] Updated 179 strings in 7 languages (fr, nl, cs, el, da, de, it)
refs #6662 ignore less files when using Piwik via bower
Merge pull request #6587 from piwik/removeHtmlMessageException

Refactor out HtmlMessageException
refs #6577 update minified piwik.js
Merge branch '6577' of github.com:piwik/piwik into 6577
Merge pull request #6659 from piwik/6577

 Return HTTP 204 instead of GIF for JavaScript tracking.
Fixed translation in test
Moved integration tests to namespaces
Removed usage of \FakeAccess in favor of Piwik\Tests\Framework\Mock\FakeAccess
Removed usage of Piwik\Tests\Fixture (deprecated) in favor of Piwik\Tests\Framework\Fixture
Deprecated root test classes because they have been replaced by namespaced ones
Fixed integration tests
Fixed integration tests
#6665 and #6670 Missing translation key in JS