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
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
refs #6661 initial work on triggering a 400 bad request instead of 500 in case Idsite is wrong
refs #6661 in case value is empty set a default
refs #6661 undoing this change to hopefully avoid some merge problems
Merge pull request #6659 from piwik/6577

 Return HTTP 204 instead of GIF for JavaScript tracking.
Fixed translation in test
refs #6661 added a test to make sure it works
refs #6661 changed it to return an HTTP 500 code as 505 is not really correct I think
refs #6661 also return HTTP 400 when idsite is 0
refs #6661 also return a HTTP 400 in case there is another invalid request param
refs #6661 forgot to commit a file and if not suppported param is used is actually a server error not request error