Fix links and parentheses don't work well together

[gaebel]

Continues #79, Fixes #78

Summary by @AndreasVerhoeven

• we count the number of opening and closing parentheses in the link
• if we have more closing parentheses than opening parentheses
• AND if there are closing parentheses at the end of the link, we assume they should originally have been outside of the link and be part of the regular text

This seems to work well in practice: Almost all links with parentheses have them balanced (e.g. wikipedia links), and links surrounded by () now work correctly as well

I've fixed the merge conflicts and changed the replaceDefault method to use generics

In addition to that:

• Fixes an issues with inline parentheses of the link text and url
• Adds https as scheme if it is missing

Planning to add:

• Ability to provide a default scheme

[benjohnde]

LGTM, just one small question arose during that review!

[benjohnde]

Ah, never mind :) LGTM!