In the new implementation, variable arguments are not removed until the end of the function. This allows variable argument processing to be restarted, and it prevents the addresses of local variables from changing in the middle of the function. The requirement to turn off stack repair code around varargs functions is also removed.
This fixes#58.
This was not working because floating-point arguments are really passed in the extended format, but based on the wording in the C standard a type of "double" should still work for arguments passed with that type.
This fixes#29. (The bug report was valid only with respect to double, not float or long double.)
*Use a typedef rather than a macro definition for va_list. (The C standards specify that va_list is a type, although this would make a practical difference only if someone #undef'd it.)
*Don't include a semicolon in va_start(), so it expands to an expression rather than a statement. This could make a difference in a construct like "if (...) va_start(...); else ...".
