Rex::Text::uri_encode - make 'hex-all' really mean all.

'hex-all' encoding was previously ignoring slashes.  For example "a/b" would return "%61/%62" rather than the expected "%61%2f%62".

This pull adds 'hex-noslashes' mode which carries forward the previous functionality, and replaces all existing references to 'hex-all' with 'hex-noslashes'  It then adds a replacement 'hex-all' mode, which really encodes *ALL* characters.