Remove global static variables

[Jesper Öqvist]

Global static variables prevent JastAdd from running concurrently, or even in sequence, in the same VM. For example, in Attributes.jrag there is currently a global static string tracking error messages. If this is not properly reset, the next JastAdd instance running in the same VM will possibly halt and report incorrect error messages.

The problem even more severe for concurrent JastAdd instances.

[Jesper Öqvist]

Removed global static error accumulator string: 2b647e98b88f04149d2a5a5306eb7b8f42660ec0

The global static indentation string needs to also be removed.

[Jesper Öqvist]

Removed global static indentation variable

fixes #123

→ <<cset 9825a6b2edc4>>