v0.5.6

This is a bugfix release that fixes a long-standing bug causing shards to
randomly die under certain rare conditions when dispatching the Ready event,
and compilation of the cache and client features without the framework
feature. This also contains an internal rewrite of the HTTP module.

The minimum required rustc version is now pinned at 1.25.0.

Thanks to the following for their contributions:

• @acdenisSK
• @Erk-
• @Lakelezz
• @Mishio595
• @Roughsketch
• @zeyla

Upgrade Path

Per c:01e3c33, Context::edit_profile has been deprecated. Call
serenity::http::edit_profile instead.

Added

• [model] impl AsRef<MessageId> for Message (@Mishio595) c:1de3937
• [model] Add From impls for Game, genericify Game params (@zeyla)
  c:e1332a5, c:a4c3fec
• [http] Make http::fire, http::request public (@zeyla) c:0d55363
• [framework] Add no-parse getters and advancer to Args (@acdenisSK)
  c:73ab20f
• [model] Add support for new PRIORITY_SPEAKER permission (@Erk-)
  c:2179623

Fixed

• [client] Don't delay Ready event with cache enabled (@zeyla) c:12d5321
• [framework] Handle no delimiters in Args (@acdenisSK) c:e5ea6c1,
  c:9568e3b
• [client] Add missing mut, fixing no-framework compilation (@acdenisSK)
  c:90c7ec4
• [framework] Check if message is empty in Args (@acdenisSK) c:0501020
• [client] Fix potential cache deadlocking when dispatching (@zeyla)
  c:f064d65
• [framework] Pass failed sub-command to default command (@Lakelezz)
  c:db21036
• [framework] Fix default command upon shortcut prefix (@Lakelezz) c:8f128b2

Changed

• [client] Deprecate Context::edit_profile (@zeyla) c:01e3c33

Misc.

• [model] Fix ChannelId::send_message's dead links (@acdenisSK) c:7a93557
• [model] Add note about cache in UserId::get docs (@zeyla) c:e2873c8
• [general] Reduce required rustc to 1.25.0 (@zeyla) c:f3f22d7, c:b324774
• [model] Make GuildId::member use cache when possible (@Roughsketch)
  c:21eb42f
• [framework] Reword some StandardFramework::complex_bucket docs
  (@acdenisSK) c:02de778
• [framework] Internally refactor positions (@acdenisSK) c:2a6c3b1
• [framework] Update Configuration default value listings (@zeyla)
  c:602c5a7
• [http] Maintain a single, re-used HTTP client (@zeyla) c:8c0e5a3
• [http] Redo the HTTP module internally (@zeyla) c:a0b0dd2, c:4648f58,
  c:8918201, c:8301333, c:bbbf638, c:9a863bd, c:c458099, c:aa437d4
• [docs] Don't return Result from tests (@acdenisSK) c:e290b03
• [docs] Fix all dead links in permissions (@Erk-) c:869fff5