Fixed long e-mail message extending 1000 lines.

- Added quoted_printable crate to encode the e-mail messages.
- Change the way the e-mail gets build to use custom part headers.

Split up long line to stop SMTP from breaking

Reorganized the icons code a bit.

Return 404 instead of 400 when no accounts breached.

Trim spaces from admin token during authentication and validate that the admin panel token is not empty

Added newlines to config options to keep them a reasonable length.

Update vault to new version. No need to wait for a release when even the official web vault is already using it

Armv6

Minor typo fix conect => connect

remove some unneeded mutability

Allow the Admin token to be disabled in the advanced menu

Print a warning when an env variable is being overriden by the config file, and reorganize the main file a bit.
Modified the JWT key generation, now it should also show the output of OpenSSL in the logs.

Add an option to not enable WAL (should help in #399)