(chat/matterircd) Updated 0.18.4 to 0.19.4

# v0.19.4

## Bugfix

- slack: fix regression with slack library (#264)
- slack: fix an unexpected panic (#263)

# v0.19.3

## Enhancement

* general: Add UPDATELASTVIEWED command, and make DisableAutoView work consistently (#255)
* slack: Handle message edits and deletion (#260)
* slack: Add handling of reactions, stars and pins (#229)

## Bugfix

* mattermost: Fix a panic #247
* mattermost: Fixes incorrect users because of paging. #244
* mattermost: Fix outdated channel issue
* mattermost: Add paging so we can see > 200 users in a channel #248
* mattermost: Fix expired session panic #259
* general: Fix datarace #246
* general: Fix empty JoinInclude
* general: Fix panic #257

This release couldn't exist without the following contributors:
@Aketzu, @bucko909, @42wim

# v0.19.2
## Enhancement
* general: Add a default value matterirc.toml for the '-conf' flag (#240)
* slack: library updated
* mattermost: library updated
* mattermost: Add support for channel created/deleted events

## Bugfix
* mattermost: Remove ourselves from the channel when removed in mattermost. Fixes #233
* mattermost: Add/remove ourselves to the channel if we join using the GUI. #239
* mattermost: Update topics in mattermost. Closes #241
* mattermost: Fix pastes and attachments in direct message. Closes #228
* mattermost: Update channels if not known on join yet

# v0.19.1
## New features
* mattermost: Added support for disabling of automatic view flag updates (#226). See DisableAutoView in matterircd.toml.example
* slack: Add message showing enhancements and add slackbot to all channels (#230)

## Bugfix
* general: Fix tight loop (100% CPU). Closes #231

# v0.19.0
## New features
* irc: Add support for spoofing query messages. #195
	* You can now see your own messages you've typed on slack/mattermost web in irc
* irc: Add PasteBufferTimeout option (send ascii-art!)
   	* See matterircd.toml.example for an example.
   	* PasteBufferTimeout specifies the amount of time in milliseconds that messages get kept in matterircd internal buffer before being sent to
   	 mattermost or slack.  Messages that will be received in this time will be concatenated together
   	 So this can be used to paste stuff like ascii-art or code.
   	 Default 0 (is disabled)
   	 Depending on how fast you type 2500 is a good number

## Bugfix
* slack: Correctly handle different nick and username #203
* slack: Ignore channel join messages #198


(mef)