[AD] explicit prefixes on structure field names

[Peter Wang <tjaden@xxxxxxxxxx>]

Hi,

In another project I work with there are prefixes on structure field
names, which are different for each structure type.  I find this greatly
helps when reading code because you instantly know which structure the
field is part of.  It also helps with ctags and grep.  Would we be
willing to adopt this convention for 4.3 code?

Attached is an example against Elias's xdummy branch.  For example, all
AL_SYSTEM_INTERFACE fields might begin with "sysif_".  I think the
benefit is quite clear, for example, in the line:

-    active = driver->initialize(0);
+    active = driver->sysif_initialize(0);

Peter