Nested classes support

Closes #89
Squash merge branch 'master' of https://github.com/wkalinin/swig into wkalinin-nested

By Vladimir Kalinin
* 'master' of https://github.com/wkalinin/swig:
  CPlusPlusOut mode for Octave
  nested class illustration
  fixed "Abstract" flag for nested classes added an example enabled anonymous nested structs runtime test
  porting
  warnings disabled
  porting fixes
  java runtime tests ported
  nested class closing bracket offset fixed
  removed double nested template (not supported by %template parsing)
  template_nested test extended
  parent field made public
  property access fixed
  replaced tabs with spaces
  warning W-reorder
  deprecated warnings removed, derived_nested runtime test added
  optimized string indenting
  Nested classes indenting
  nested classes docs
  fixed the order in which flattened inner classes are added after the outer
  Private nested classes were getting into the type table.
  Java getProxyName() fix for nested classes fixes the case when nested classes is forward declared
  Fix for a case when a nested class inherits from the same base as the outer. (Base class constructor declaration is found first in this case)
  merge fix
  nested C struct first immediate declaration incorrectly renamed sample fixed
  tests updated to reflect nested classes support
  Java nested classes support (1)
  flattening should remove the link to the outer class
  access mode correctly set/restored for nested classes
  nested templates should be skipped while flattening (template nodes themselves, not expanded versions) also non-public nested classes should be ignored
  If nested classes are not supported, default behaviour is flattening, not ignoring flag "nested" is preserved, so, the nested classes can be ignored by user
  nested workaround test updated
  template instantiated within a class is marked as nested for ignoring purposes
  %ignore not applied to the nested classed, because "nested" flag is set too late
  typedef name takes precedence over the real name (reason?)
  unnamed structs should be processed for all the languages
  nested C struct instances are wrapped as "immutable"
  tree building
  typedef declaration for unnamed C structures fixed
  nested classes "flattening"
  fixed %ignoring nested classes
  renamed "nested" attribute to "nested:outer" added "nested" flag, to be used with $ignore (it is not removed while flattening) added nestedClassesSupported() function to the Language interface
  renamed "nested" attribute to "nested:outer" added "nested" flag, to be used with $ignore (it is not removed while flattening) added nestedClassesSupported() function to the Language interface
  tree iteration fix
  dirclassname variable names unified memory issue fixed
  merge error
  ignore unnamed structs for C++
  unnamed nested C structs naming & unnesting
  class added to classes hash under typedef name
  private nested classes skipped
  test updated due to nested templates support
  anonymous structs with inheritance fixed nested_class test to allow anonymous structs w/o declarator
  tests updated: nested workaround removed from namespace_class.i propagated nested template declaration to the C++ file
  injected members scope
  nested tempplates fixes, nested structures in "C" mode parsing added utility function "appendSibling" (like "appendChild")
  nested unnamed structures parsing fixes, access mode restored on nested class end, tdname is properly patched with outer class name prefix
  memory management fixes
  nested templates (1)
  Nested unnamed structs
  Nested class support (1)
  Nested class support (1)
Cosmetics/code beautification of nested class support
Minor code improvements
Add C++ nested class example

This also reverts the nested class additions to the Java/C# 'class' example
so that the 'class' example remains identical across different language modules
Add in Travis testing for nested branch
C nested struct passed by value example

This was causing problems in Octave as wrappers were compiled as C++.
Solution has already been committed and required regenerating the inner struct into
the global C++ namespace (which is where it is intended to be in C).
Testcase of private nested class usage causing segfault

Needs fixing for C#/Java
fixed out-of-scope nested class definitions, added a test
enabled nested C structs assignment (still disabled for Octave), added Java runtime test
fixed nested_private test case for Java & C#
out-of-scope template definitions fixed
nested_private test disabled again
nested private classes are discarded while parsing
nested relate functions are moved to nested.cxx and renamed accordingly
Swig_offset_string moved to misc.c
Minor tweaks in Swig_feature_set
Fix template partial specialization detection

Fixes template definitions that should be ignored and warnings introduced after nested changes:
../../../Examples/test-suite/refcount.i:63: Warning 318: Instantiation of template 'RCPtr< A >' is ambiguous,
../../../Examples/test-suite/refcount.h:159: Warning 318: instantiation 'RCPtr< T >::RCPtr' used,
../../../Examples/test-suite/refcount.h:159: Warning 318: instantiation 'RCPtr< T >::RCPtr' ignored.
../../../Examples/test-suite/refcount.h:159: Warning 318: instantiation 'RCPtr< T >::RCPtr' ignored.
../../../Examples/test-suite/refcount.h:159: Warning 318: instantiation 'RCPtr< T >::RCPtr' ignored.

Different/clearer implementation of constructor detection since Classprefix is
not behaving the same since nested changes were introduced. Only accept
constructors if in extend mode or in a class.

Also remove unused "isextension" attribute on the nodes.
Classprefix fixed after private nested classes
some comments and spaces added
Merge branch 'nested' of https://github.com/swig/swig into nested
Nested C class setters restored in c++out mode for Octave

Suitable casts are required so that assignment of instances of nested classes
work as the nested class is duplicated in the global namespace, eg:

struct Outer {
  struct Nested {
    int bar;
  } bar_instance;
};

Outer.bar_instance can now be assigned to.
Add missing header to new source file
Ensure -c++out is not used with -c++

Error checking for this combination implemented as well as correcting
Octave

Also refactor, replacing CPlusPlusOut variable with cparse_cplusplusout
for an implementation which more closely resembles cparse_cplusplus which
is also required in both .c and .cxx files.
Add check-c and check-cpp targets for running just C and C++ test cases
Minor expansion of nested C structs testing