The URI where data should be posted is not specified, it may be "/" for example if the whole server
is dedicated to RPC processing. The payload is in XML, a single "methodCall" structure. The "methodCall"
must contain a "methodName" sub-element, a string containing the method to be called. It is entirely
up to the server to decide how to interpret the characters in "methodName". For example it could be
the name of a file to excute, the name of a row in a database, or anything else. If the procedure
receives parameters the "methodCall" may contain a "params" element with 1 to N "param" sub-elements,
each "param" element may have a value with a type indicator that can be:
<i4> or <int>
four-byte signed integer -12
0 (false) or 1 (true) 1
ASCII string hello world
double-precision signed floating point number -12.214
base64-encoded binary eW91IGNhbid0IHJlYWQgdGhpcyE
A value may also be a struct:
A <struct> contains <member>s and each <member> contains a <name> and a <value>.