vchoi_fork

[svn-r9755] Purpose:  New feature

Description:  Start to support software conversion between long double and
all integers.

Solution:  No major changes to the algorithm.  Changes to configure is to
exclude SGI for long double to integers test because there're too many problems
in their compiler.

Platforms tested:  h5committest, modi4, fuss, Teragrid, arabica

Misc. update:  RELEASE.txt