Bert RPC access and argument conversion

Bert manage MFA access list.

{accept, Mod} {accept, Mod, Func, Arity}

{reject, Mod} {reject, Mod, Func, Arity}

{redirect, [ {M, M'} | {{M,F,A},{M',F',A'}} ]}

Mod == {accept, Mod} {M,F,A} == {accept,M,F,A}

{propargs,Mod,Func,ArgSpec} ArgSpec = keep | [Arg | ArgSpec]

Arg = Name::atom() | {args,ArgSpec} -- get nested arguments | {opt,Name::atom(),Default::term()} | {Convert, Name::atom()} | {Convert, Name::atom(), Default::term()}

Convert = string_to_integer | | string_to_float | | string_to_atom