Rune - Add multi-character single-quoted constants

Rune - Add multi-character single-quoted constants

* Supports multi-character single-quoted constants.  Constants
  between 1 and 4 characters are directly encoded by shifting
  each character into the LSB.  The type depends on the length:

  length 0 or 1		uint8_t
  length 2		uint16_t
  length 3 or 4		uint32_t

* Character constants that are 5 characters or longer will be hashed with
  the ISCSI crc32 algorithm, bit 31 of the result is set, and the result
  is returned as an unsigned 32-bit integer.