Version 2 buffer formats

VERSION=2 must be specified on the IEWBUFF macro to obtain buffers in this format.

Most buffers have not changed except for the version number, but VERSION 2 is supported by IEWBUFF for all classes, whether or not there is a format change. Differences between Versions 1 and 2 include:

ESD and RLD buffers have changed significantly in support of multiple text classes, a new binding algorithm and new address constants.
A new binder-defined class, B_MAP, describes the logical structure of the program object.
External names can be up to 1024 bytes in length.
@class-type class names are not supported in version 2 calls and buffers.
For compatibility with PM1, the PM2 IEWBUFF macro produces the Version 1 buffer formats, described previously, if VERSION=1 is specified or defaulted in the macro invocation.

This section contains the buffer layouts that have changed or have been added in version 2. As indicated in Table 2, all other buffer formats are the same for version 2 as in version 1.