v2.16

Minor bugfixes -

Fix an unwind problems when DW_CFA_restore is issued when there's no default disposition for the restored register in the CIE.
Fix unchecked error when tracing a live process if that process dies, and reading from its memory fails
Remove a lot of the crud that pretended to support the pre-nptl threads model.
Minor formatting changes.

Full Changelog: v2.15...v2.16