Remove all plain calls to H5Gopen() from source, replacing them with
either H5Gopen2().
Add test for H5Gopen1().
Reformatted several pieces of code, to clean them up.
Tested on:
FreeBSD/32 6.2 (duty)
FreeBSD/64 6.2 (liberty)
Linux/32 2.6 (kagiso)
Linux/64 2.6 (smirom)
Solaris/32 5.10 (linew)
Mac OS X/32 10.4.10 (amazon)