Merge pull request #1009 from ariard/2021-07-add-forward-dust-limit

Add new config setting `max_balance_dust_htlc_msat`

diff --cc fuzz/src/chanmon_consistency.rs
Simple merge

diff --cc lightning/src/ln/channel.rs
Simple merge

diff --cc lightning/src/ln/functional_test_utils.rs
Simple merge

diff --cc lightning/src/ln/functional_tests.rs
Simple merge