avoid all new relic transactions to be named index.php

https://docs.newrelic.com/docs/php/php-agent-faq#wt-naming
Don't use get parameters in the transaction name

This will avoid this error: "Your application has more web transactions than we can usefully display (showing ... out of ...). Some data on this page will not be accurate. "
Name 404 as 404 in newrelic

This will avoid that all custom non-existing URL's will have their URL as transaction name in New Relic. All 404 pages look the same and the same code is executed, so I prefer naming them all 404 and avoiding this error: "Your application has more web transactions than we can usefully display (showing 2250 out of 2279). Some data on this page will not be accurate. "
New Relic: Mark cronjobs as background jobs
Newrelic: use module::action as transaction name

This way, not all detail pages will get a seperate transaction in New Relic.
Remove unwanted trailing space.
New Relic: Give ajax actions a transaction name

They'll be called ajax::module::action
New Relic: Give cronjobs a better transaction name

they'll be called cronjob::module::action
Merge pull request #670 from WouterSioen/patch-15

avoid all new relic transactions to be named index.php