Added bluArray interface, other improvements

* Add 'bluArray' Interface to allow handling of varying instances of
bluArrays that implement different strict types (e.g. 'bluArrayLongs',
'bluArrayDoubles' ...)
* Added 'bluBinary'. This will be to binary files what 'bluString' is to
Strings
* Changed bluString's format marker to avoid clashes with single dollar
signs followed by a marker