where a newly opened line would immediately get wrapped out of existence.
The old method of handling lines in a multiline field did not cope with
this elegantly.
* Added new field flag O_REFORMAT which, when set, returns the field
buffer with newlines inserted where the line wrapped. Previously, there
was no way of preserving the on screen format of a multiline field.
* Added new file gdbinit which contains a macro to verify and print
the multiline field line data structure.
* Bumped libform major number due to changes in the _form_field structure.