This PR deprecates the cmpr and bxp functions and makes the ExpressionBuilder callable. eb can now be used to create all sorts of binary expressions. I didn't change the site examples yet, or otherwise they would be broken until we release this.

This PR also removes the deprecated orWhere, whereExits etc. methods. It might be a bit early to do that, but didn't find a way to make the expression builder callable while they existed.

The second commit introduces an alternative way to create and and or expressions. The old way is still there and won't be removed or deprecated. Some people prefer that one and it's (at least currently) much easier to create conditional or-expressions using the or([expr1, expr2]) function.

These changes now make simple or statements fluent and arguably more readable:

// The "old" way
db.selectFrom('person')
  .selectAll()
  .where(eb => eb.or([
    eb.cmpr('first_name', '=', 'Jennifer'),
    eb.cmpr('last_name', '=', 'Aniston')
  ])

VS

// The new way
db.selectFrom('person')
  .selectAll()
  .where(eb => 
    eb('first_name', '=', 'Jennifer').or('last_name', '=', 'Aniston')
  )

You can still destructure eb. eb contains a property eb that refers to itself:

db.selectFrom('person')
  .selectAll()
  .where(({ eb, or }) => or([
    eb('first_name', '=', 'Jennifer'),
    eb('last_name', '=', 'Aniston')
  ])

closes #494