Checksums

Adds the checksum checking.
If a plugins checksum is in the database it will be skipped, premium plugins will always be scanned no matter what however due to the Anti-Piracy spigot implements in them. If a plugin/plugin update ISN'T in the database, it will be scanned.

[3.30]

Fixes an issue related to plugin.yml files breaking things, instead of halting the entire program it will just log to console