Libdwarf version 0.4.0

[davea42]

Changes to 6 interfaces to make 3 dealloc functions be named with a pattern consistent with the rest of libdwarf, a function reverted to a pre-DWARF5 version for correctness, and changes to the .debug_names API functions to enable full access to the section.

Details on the changes are in the Recent Changes section of libdwarf.pdf

dwarfdump now prints all the information in .debug_names with --print-debug-names.

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This discussion was created from the release Libdwarf version 0.4.0.