This is a simple expansion expanding to the name of the interface and is
not qualified like $javainterfacename and $csinterfacename.
Expansion within typemaps is much like $javainterfacename otherwise.
Note that expansion within the pure java code typemap,
'javainterfacecode' and similarly pure C# code typemap,
'csinterfacecode' works like $javaclassname/$csclassname and
$&interfacename should not be used, just $interfacename.
Support expansion of name attribute in: %feature("interface", name="%s")
%s expands to the proxy class name and all the usual %rename functions
can be used (regex, strip, camelcase etc) to derive the interface name
from the proxy class name.
Rename $interfacename family of special variables to $javainterfacename for Java
Rename $interfacename family of special variables to $csinterfacename for C#
This is to free up $interfacename for simple interface name expansion in forthcoming commit
The C++ type must be last in the argument list to support templates with
multiple arguments which are separated by commas.
Affects DECLARE_INTERFACE and DECLARE_INTERFACE_RENAME.
