* MM-16369: include potential subpath in emails
Various email templates were extracting the `Host` but not the `Path` from the SiteURL, excluding a potential subpath defined therein.
* improve coverage of condenseSiteURL
* Implementation to Make all Mattermost system emails Multi-Part, with both a HTML and Plain Text version
* update lib
* update code per review
* update to use the mattermost repo
* Adding initial race detector
* Remove setting of config twice
* Fixing config file watch and config reload on license save
* Fixing config file watch and config reload on license save
* Fixing build error
* Fixing locking issue
* Fixing makefile
* Fixing race in config
* Fixing race in status unit test
* Adding EE race tests
* Fixing race in cluster info
* Removing code that's isn't needed
* Fixing some more races
* Fixing govet issue