hdf5_ep

[svn-r18470] bug fix:
recent changes to the embedded library generation code does not quite work
for the AIX system. The strings command of AIX does not display the embedded
library information be default.

Solution:
Changed the H5libhhdf5_setting[] to be an extern variable. Also removed the
const qualifier so that strings can see the variable data.

Tested:
Blue-print (with embedded-libinfo enabled and disabled).