vchoi_fork

[svn-r12154] Purpose:
Removed -march flag

Description:
The -march optimization flag is bad in some circumstances

Solution:
Prevented HDF5 from adding the -march archicture-specific optimization
flag, so that users could have one version of HDF5 used by
several different machines.

Platforms tested:
heping (one of the few platforms that affected by this small change)