Bump to Electron 4.1.4

Update Changelog

Switch to 39-character message IDs to fix iCloud “SMTP black hole” is…

…sues

Detailed writeup of this found here: https://medium.com/follow-up-boss-dev/when-icloud-emails-go-into-a-black-hole-76991abd87a8. Mailspring was previously sending message IDs where the “local part” was 46 characters.

Using UUIDv4 because it exactly matches what iCloud itself is using.

Fix regression on some linux distros - need to set curl CURLOPT_CAINFO

Attach a small menu to the preview windows, remove scrollbars on Windows

Enable automatic selection of pt-BR in Brazil

Update Changelog, cut v1.5.3 release

Fix localization of templates notice to remove "

Bump to 1.5.1, update Changelog

Update changelog