Long lambdas should have a parameter name instead of it

[petertrr]

• Count number of lines in lambda
• If it's more than maximum, suggest to replace it with explicit parameter name
• Make maximum size configurable
• Describe it in code style guide in chapter 5

Invalid code:

list.map {
    // over 9000 LOC
}

Valid code:

list.map { element ->
    // over 9000 LOC
}