* WIP Implementing new event subscription API
* back to lifetimes, fix example
* no more need for accept_weak_inclusion
* thread lifetime through to prevent 'temporary dropped' issue
* make working with events a little nicer
* Get tests compiling
* fmt and clippy
* _name back to name
* dont take ownership, just have stronger note
* Attempt to fix test
* remove commented-out code
* Add a couple more helper methods and a test
* Remove custom ExtrinsicFailed handling; treat them like other events
* Handle runtime errors in TransactionProgress related bits
* cargo fmt + clippy
* Fix some of the failing tests
* remove unused import
* fix transfer_error test
* Fix compile errors against new substrate latest
* Comment tweaks, and force test-runtime rebuild
* Drop the TransactionProgress subscription when we hit 'end' statuses
* cargo fmt
* find_event to find_first_event and helper to return all matching events
* TransactionProgressStatus to TransactionStatus
* Copy and improve docs on TransactionStatus from substrate
* debug impl for Client to avoid manual debug impls elsewhere
* Add and tweak comments, specifically a note about block inclusion on errors
* clippy + fmt
* Fix docs
* Ignore 'error' statuses and adhere to the substrate docs
* tweak and improve some comments per @dvdplm's suggestions
* Break transaction* structs into separate file
* fmt and fix doc link
James Wilson