Security update for libXfont (important)

LibXFont was updated to fix security problems.

Following security issues were fixed:

• CVE-2015-1802: The bdf parser reads a count for the number of properties
  defined in a font from the font file, and allocates arrays with entries
  for each property based on that count. It never checked to see if that
  count was negative, or large enough to overflow when multiplied by the
  size
  of the structures being allocated, and could thus allocate the wrong
  buffer size, leading to out of bounds writes.

• CVE-2015-1803: If the bdf parser failed to parse the data for the bitmap
  for any character, it would proceed with an invalid pointer to the
  bitmap data and later crash when trying to read the bitmap from that
  pointer.

• CVE-2015-1804: The bdf parser read metrics values as 32-bit integers,
  but stored them into 16-bit integers. Overflows could occur in various
  operations leading to out-of-bounds memory access.