Corrected the handling of lengths for which no plaintext passwords are known.

Added the previously missing zeroization of the crack counters (alternatively,
we could revise the loops that follow to always write into all crack counters,
but this is more complicated and is likely slower).
Corrected a typo in a comment
In fix_state(), copy numbers up to rec_length only (for speed when the current
length is much lower than CHARSET_LENGTH)
In expand(), check against real_min and real_size to detect erroneous or
malicious charset files that use characters other than those they have listed
in allchars.  The check against CHARSET_MIN and CHARSET_SIZE was no longer
sufficient for safety against bad charset files now that we skip initialization
of array elements outside of the real_* range.
1.7.9.9:
- Incremental mode has been revised
Added __inline__ to the recent gcc specific version of the MAYBE_INLINE macro,
in addition to __attribute__((always_inline)).  Apparently, the attribute alone
is not sufficient for gcc 4.7+.
Added a comment about the commented out "OMPFLAGS = -fopenmp -msse2" line
Enable triop on AVX
Added "for this build" to the error message saying "<CPU type> is required"