Add default __eq implementation

* Renamed SWIG_Lua_equal to SWIG_Lua_class_equal
* If class has no __eq implemented, then default __eq is provided.
  Default __eq compares actual pointers stored inside Lua userdata
Moving variable declaration to the beginning of the block
More tests for equality operator overloading
%extend symbols for nested structs get into a wrong C symbol table
Test-suite makefile fixes for Windows

Remove $(realpath ) which is no good for Windows executables running
under Cygwin's make
CCache: always generate docs in source directory
Distclean Tools/javascript
Fully clean Go test-suite
Fix Javascript examples so that "make clean" works properly with node

- Need to copy example.cxx to build directory so that build products
  end up in the right place; use a gyp command expansion to do so
Fully clean Javascript test-suite with jsc and v8
Fully clean PHP test-suite
Fully clean Python examples and test-suite
Set SRCDIR when calling test-suite clean targets, in case it's needed
Add check-maintainer-clean target: fails if files are missed by maintainer-clean
Fix infinity testcase on windows
Correct infinity testcase
Fix errors test-suite on windows
check-maintainer-clean: print skipping message for in-source-tree builds
Fix cleaning of Python runme.py scripts for in-source-tree builds
Search for 64bit webkit during configure

For some Linux distributions (SUSE)