doc: Update version/CHANGELOG for 0.7.2

doc: Update version/CHANGELOG for 0.7.1

doc: Update changelog with extra breaking change

build: Depend on the minor version of backtrace

Otherwise this causes nasty conflicts up the dependency chain

doc: Update version/CHANGELOG for 0.5.5

doc: Update CHANGELOG and version for 0.5.4

doc: Update CHANGELOG and version for 0.5.3

doc: Update webbluetooth part of README

doc: Update changelog and roll version to 0.5.1

doc: Fix comment in example for channel system