Now base::lambda can be copied and can wrap any immutable lambda.
For mutable lambdas there is base::lambda_once (which you're
supposed to call only once to pass data through lambda captures,
for example by using std::unique_ptr). Generally base::lambda is
passed by value and base::lambda_once is passed by rvalue reference.
All errors that lead to MTP request resending by default
error handler now can be handled differently. For example
inline bot requests are not being resent on 5XX error codes.
+ extensive use of auto keyword in MTP types handling.
John Preston