version 0.6.1
 speed improvement using zero-excess initial state. (2010/1/15)
 change print format specifier (2010/1/20)

version 0.6
 All global variables are moved into structures. (thread safe or thread independent) (2009/12/15)
 lenstra algorithm is replaced by pivot_reduction algorithm. (2009/12/15)
 Interface changed (2009/12/15)
 Revive old interfaces (2009/12/22) CAUTION:old interfaces are thread unsafe.

version 0.5
 A bug delete_mt_array() in lib/seive.c is fixed. (2009/3/24)
 A bug _sgenrand_dc() in lib/mt19937.c is fixed. (2009/3/24)

version 0.4
 A bug in sgenrand_mt() in lib/genmtrand.c is fixed. (2007/8/11)

version 0.3
  ``uint32'' is replaced by ``uint32_t.'' (2006/11/27)

version 0.2.1
 ``inttypes.h'' is included.
 typedef unsigned int uint32; --> typedef uint32_t uint32;
 A C99 complier is required. (2006/11/18)

version 0.2
 _sgenrand_dc() in lib/mt19937.c is changed. (2002/2/21)
 sgenrand_mt() in lib/genmtrand.c is changed. (2002/2/21)

