Fix elytron properties help

[gsmet]

No rocket science but let's get these properties right.

[gwenneg]

I know it's not part of your changes, but do we really need all those getters and setters? :) If yes, shouldn't the plainText field also have its getter and setter (and be part of the toString method)?

[gsmet]

I know it's not part of your changes, but do we really need all those getters and setters? :) If yes, shouldn't the plainText field also have its getter and setter (and be part of the toString method)?

Yeah, let's try to clean this up.

[gsmet]

@gwenneg done.