[Idea] Provide a precompiled gem for Mac OS X and Linux

[andyundso]

There are a bunch of open issues (and assume many more closed ones) about how to install and use tiny_tds. If we would provide a precompiled gem (similar to the one for Windows today), people would not have to install FreeTDS themselves and those type of issues are a thing of the past.

Considerations:

• I would like to issue more frequent releases simply to keep the dependencies up-to-date.
• CI pipeline to automatically build and test all of these variations would take considerably more time.
• People currently have some freedom how they want to build their FreeTDS environment (e.g. with or without SSL support). By providing a precompiled gem, these choices are already made for people.
• Instead of getting issues "how do I install" it could be more "it does not work".

In any case, we need to add the LICENSE for the dependencies into our distributed version to comply with GPL.