Allow to skip url parameter encoding for custom type

[fracz]

Currently, there is no way of using custom characters in URLs like proposed here (using ✓ for true and ✖ for false values). Every value is passed through encodeURIComponent() call here and there is no way to skip it. Custom types should have an ability to skip URL encoding when desired.

This is somehow related to #1119.

[nateabele]

This is implemented with raw types in 1.0.