Remove restriction requiring FROM specification before JOIN

[elazar]

Presently, when building a SELECT statement, from() must be called before join(). My understanding is that this is more for semantic (i.e. JOIN essentially being a sub-clause of FROM) than logical / logistical reasons. There are use cases that would be supported by not having this restriction.

While I may attempt implementing this myself at some point, I'm uncertain of how soon that will be. As such, I'm filing this issue in case anyone else runs into the same situation and/or wants to try to implement it themselves.

[pmjones]

Well, it's been a year. @elazar do you feel this is still something that's needed? Or is it a doc fix, where we say "you must call from() before join()" ?

[elazar]

I'd call it a "nice to have." If a code change isn't made, a doc change probably should be.

[pmjones]

@elazar Please review PR #96 , which is an attempt at fixing this issue.

[pmjones]

Fixed by #96; please open a new issue if it doesn't work the way it should. Thanks!