#111 Dropping support for older runtimes

[FreeAndNil]

• changed target frameworks to net462 & netstandard2.0
• added release notes for 3.0.0
• resolves #111

[FreeAndNil]

@fluffynuts I've executed steps 1 & 2 of releasing.md

Could you take a look?

Thanks

[fluffynuts]

Will do

[fluffynuts]

I'm wondering if we shouldn't try get out a 2.x release before this - just release off of master. Perhaps even one more after that (there was an issue with mssql introduced by some update to make pgsql better, to do with when parameterisation is done (I forget the rest of the details)).

At the very least, it would solve the "when will this patch be released" questions. Let's keep this branch around though - I want to simplify build, and you've done the right thing (imo) with the major version bump. If there's some really good reason to revive a 2.x release, we could then also use the last release tag as a starting point. What do you think?

[FreeAndNil]

That's a good Idea. I will separate the release note changes into a separate branch and adjust them to a 2.16.