Code shouldnt use _GET and _POST directly but fetch them via a helper method

[mattab]

AS part of #2135 I discovered the joy of inconsistencies between browsers (Firefox decodes URL hash, while others don't) and inconsistencies in PHP (_GET is URL decoded by default, so we can use _SERVER[QUERY_STRING] to access raw value.

To prevent further problems in the future and keep other devs from experiencing my pain, I'd like to change the codebase so that no one uses _GET or _POST directly but always ask a helper method.

[mattab]

In 263892f: Refs #2135

• NAILED the encoding! wow that was tough for my brain, but finally got around it.

  Some findings:
  _GET is automatically URL decoded
  QUERY_STRING contains raw URL so we'll use this one instead
  I REALLY want to simplify the whole "_GET" variables within Piwik so that all code uses a static method to get input variables. Refs Code shouldnt use _GET and _POST directly but fetch them via a helper method #3931

[michalkleiner]

Closing as superseded by #12620