Query builder should use back-ticks to escape identifiers

[iamjochem]

sometimes you have a field or table whose name clashes with a reserved word (hey it happens) ... proper escaping of identifiers in the generated SQL would make the pain go away.

[bjornpost]

According to the tests here we're already escaping column names in some cases. If you're using Query, we're not escaping things. Seems like inconsistency we should fix.

Table names are not escaped yet, but we have some code that returns quoted table names.

[Jud]

I have this fixed in a branch (we have an Order model, so it's pretty much a requirement to escape names). I'll see if I can cherry-pick the commits and submit a PR.