Make clock_get* functions take string argument
Make clock_get* functions take string argument

For consistency with existing functions.

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