Dmitrii

Add query logging

1

Added simplest possilble query logging. Not sure it that's enough though. What do you think?

Impl Queryable, AsExpression, From/ToSql for ranges from std

10

Hi, I implemented `Queryable`, `Expression`, `FromSql`, `ToSql` traits for `Range*` types from `std`. It would be awesome to have these types when working with various intervals in Diesel.

Is it really necessary to hide `ErrorKind`? If it's not, I've made the PR.

Higher-level and more safe API

2

Hi! Thanks for helpful library! Are there any plans to implement more higher-level and safe API? I have kind of proposal but there are many details it lacks. 1. `Plugin`...