Copyright Update + More

All - original - files have copyrights added, now. Adds license file.

OTHER CHANGES:
PlayerManager.java
Added arrays for SQL, URL, and Files, separately. This will allow users
to have multiple sources. In the process of implementing a new feature,
which allows server owners to have a message in the MotD, which displays
whether a user is whitelisted, or not.

GrimList.java
Minor update to toLog to comply with new ConfigManager.java. New method,
toExecutor, to replace constantly calling sendMessage.

Executor.java
Changes to use toExecutor(). "update" edited in advance to deal with new
toExecutor() method. Will update others later.

ConfigManager.java
Massive updates in this area.
players.txt replaced with playerdata.yml. Changes made to reflect this.
Various default configuration changes.
Information added to work with playerdata.yml.
SetVariables renamed to ConfigureVariables.
Changes made to how ConfigureVariables works.

Update.java
Changes made for toExecutor() method to be called.