Tests for "can selector become true by modifier" for simple $-operators
Fix wrong tests, separate "complex" tests to a separate scope.
Now Matcher.canBecomeTrueByModifier deals with simple $-operators with scalars:

- $gt, $gte, $lt, $lte
- $ne
- $nin, $in
More tests
Fix the way $in analysis worked
Catch if modifier surely modifies object when scalar expected
Update the comment in tests section
Fallback to "YES" in a case of noticeable floating point numbers underflow
Polish canBecomeTrueByModifier operators optimization

- Fix the pruning `expectedScalarIsObject`
- Limit $gt,$lt,... to numbers only (since there needs to be more logic to support dates and strings later)
- Add comments on dubious parts
Merge branch 'oplog-selector-modifier-operators' into devel

Brings optimizations to the oplog-tailing:
- analyze modifications coming from oplog and skip uneccessary fetches for certain $-operators
  + ranges of numbers { $gt: 5, $lt: 33 }
  + inequlities { $not: 5 } or { $nin: [ 1, 3, 4 ] } for scalars
  + equalities { $in: [ 2, 4, 6 ] } for scalars