Tagging `__tostring` improvements and EXEC/STACK options with 0.70.

Tagging path normalization, `onscratch`, and `output` changes with 0.64.

Tagging `onexit` callback and `DONE` improvement with 0.63.

Tagging vararg and deleting all breakpoints with 0.62.

Tagging DONE fixes and Lua 5.3 support with 0.61.

Tagging line mapping and nginx debugging support with 0.60.

Tagging stepping, serializing limits and LuaJIT 'main' debugging with…

… v0.55.

Tagging Lua 5.2 compatibility changes and serialization fixes with v0…

….54.

Tagging performance optimization and __serialize support with v0.53

Tagging cross-platform, Lua 5.2, and full LuaJIT debugging with v0.52.