Stop using parse_str to not accidentally decode HTML entities

[marc1706]

Fixes #50

Also removed the SEO_STRIP part as that does not make any sense anymore.

Checklist:

• [ ] Correct branch: master for new features & bug fixes
• [ ] Tests pass
• [ ] Code follows coding guidelines: phpBB coding guidelines

Describe the pull request :
Fixes issue #50

[ser]

it should indeed.

[marc1706]

This fixes the aforementioned issue while keeping the feature to remove the sid and hilit parameters.