%extend for nested unnamed C structs
test added for nested unnamed C struct %extend
global unnamed structures ignored
obscure case workaround in std::set wrapper, where ignored type still need to be processed
JavaScriptCore: ConvertPtr should allow JavaScript null to be a valid value.

It is common in C to accept NULL to functions for pointer parameters.
extern void DoSomething(struct Foo* foo);
...
DoSomething(NULL);

Thus, JavaScript null should be allowed:
module.DoSomething(null);

But the current ConvertPtr definition accepts only objects. This modifies it to allow null.
Javascript: support null pointers.

We allow to set pointer types using JS null.
JavascriptCore: Bugfix for null-pointer support.

This solution must be considered as a preliminary workaround.
Merge branch 'wkalinin-csymbols-1'

* wkalinin-csymbols-1:
  obscure case workaround in std::set wrapper, where ignored type still need to be processed
  global unnamed structures ignored
  test added for nested unnamed C struct %extend
  %extend for nested unnamed C structs
Create separate extetnd.c file for handling extensions / %extend

This is just a simple code refactor, moving and function renaming to
remove the %extend code out of the parser into its own file now
 that it isn't just used in the parser.
Add missing entries into changes files.
Python 3 byte string output: use errors="surrogateescape"

... if available on the version of Python that's in use. This allows
obtaining the original byte string (and potentially trying a fallback
encoding) if the bytes can't be decoded as UTF-8.

Previously, a UnicodeDecodeError would be raised with no way to treat
the data as bytes or try another codec.
Add "unicode_strings" test case for new Python 3 behavior
Add Python 3 'surrogateescape' documentation
Work towards C90 compatibility for Lua
Fix comment typo
Correct CFLAGS CXXFLAGS for Javascript and guile examples
Fix compiler warnings in examples when using -std=c++98 -std=gnu89 -pedantic -Wreturn-type
Fix compiler warnings in generated code when using -std=c++98 -std=gnu89 -pedantic -Wreturn-type
Javascript warnings for c++98 - remove vla
Refactor Lua class base search to make ISO c/c++ compliant