RootCertificate creation improvements

[honfika]

I'd like to implement my own Root certificate storing mechanism as in #175
Since some days ago it was possible to set the RootCertificate from outside, but I'd like to use the existing certification maker classes. (Don't want to reimplement WinCertificateMaker or BCCertificateMaker in my own code)
So I changed the Certification provider to public, which has now 3 public methods:

public bool CreateTrustedRootCertificate(bool persistToFile = true)
public void TrustRootCertificate()
public void RemoveTrustedRootCertificates()

The default behavior is the same as before, it will store the certificate to rootCert.pfx.

I was also thinking on changing the ICertificateMaker and CertificateManger.CertEngine to public, too.
Maybe it would be useful.

RemoveTrustedRootCertificates removes only the root certificates. If you use Bouncy Castle then they are all which are stored in the Windows certmgr.
But if you use Windows CertEnroll(is this the right name?) engine, It will store every single site certificate, so later it would be useful to create another cleanup method which removes them.

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• No Bugs - I made sure that this change is working properly as expected. It doesn't have any bugs that you are aware of.
• Branching - If this is not a hotfix, I am making this request against develop branch