Description:
    - Overloaded Atribute::getName to take a char* for the attribute name:
        ssize_t Attribute::getName(char* attr_name, size_t buf_size)
    - Switched the arguments in this function:
        ssize_t getName(size_t buf_size, H5std_string& attr_name)
        so it became:
        ssize_t getName(H5std_string& attr_name, size_t buf_size)
        The second argument is default to 0, and can be skipped.
    - Removed this function:
        H5std_string getName(size_t buf_size); it'll collide with the
        first function when that function takes a NULL for the first
        argument, and uses default value for the second argument.
    - Added more tests
Platforms tested:
    Linux/ppc64 (ostrich)
    Linux/32 2.6 (jam)
    SunOS 5.11 (emu)



git-svn-id: https://svn.hdfgroup.uiuc.edu/hdf5/trunk@24938 dab4d1a6-ed17-0410-a064-d1ae371a2980