Redo signal API to be more conventional, allowing signal handlers to be reset (no __newindex nonsense).
Redo signal API to be more conventional, allowing signal handlers to be reset (no __newindex nonsense).

rrthomas/luaposix,ardje/luaposix,ardje/luaposix,jimmyharris/luaposix,zevv/luaposix,jimmyharris/luaposix,zevv/luaposix,snegovick/luaposix,luaposix/luaposix,rrthomas/luaposix,snegovick/luaposix