v5.0.4

Fix singleton can no longer be used after being closed
example: prop.go handle unhandle error
prop: add EmitConst
Add more match options
Fix Conn.exportMethodTable
Improve error message in export()
Fix function documentation name
Fix spelling mistakes
prop: fix set property
sequential_handler: convert queue to from a list to a slice
sequential_handler: simplify to use less goroutines
conn: reduce channel capacity to 1 in Conn.send()
conn: centralise (most) serial handling to sendMessageAndIfClosed
Mention another project that uses godbus/dbus
Add Add/RemoveMatchSignal versions that accept a context
fix compilation error on FreeBSD 13 CURRENT
declare error type once
Remove type assertion
Add tests, catch case where developer does not handle error
Add ExportAll option so objects can ignore Error requirement
Allow the Store for Variants and Properties.
Fix panic on call to method with pointer arguments
Allow race-free implementation of the State Caching Proxy Pattern.
Add playerbm to projects that use godbus in readme
Update tests to use Connect functions
Add Connect tests
Update examples to use Connect methods
Add Connect* functions