Added test for continued attrs
Added new data type "vsa", and made Vendor-Specific use it.

This means that much code is broken, but oh well...
Fix dict_attrbyparent() to work
New decoder.

It keys off of data types, rather than having special functions.
The only special functions are there to shorten the main ones.
Just use rad_attr2vp()
Fix typo
Handle parsing Vendor-Specific = ANY
Initialize vpt->da
Added dict_attrbychild
Turn off debugging VP_TRACE