Added configuration for custom parameters in request URLs

[binlab]

Changes:

Added ENVIRONMENT parameters:

• MORTY_URL_PARAM
• MORTY_HASH_PARAM

together with the corresponding console parameters:

• -urlparam
• -hashparam

Now with this modification each instance can be configured individually for any kind of projects

Motivations:

• For security reasons, hide a proxy software type and name. Prevent leaking this data by hardcoded params name
• Customize and branding parameters for individuals together with the domain
• Possibility create nice and short URLs for system usage like: dl.io/?u=https://google.com