Introduce a JSON module (#379)

* Add JSON module

* Merge upstream changes

Fix memory leaks

* Add json include to PackageScript

* Merge upstream changes

Fix memory leaks and increase max nesting

* Fix documentation

* Use AutoPtr in managing JSON handles

* Merge upstream changes

Order of items in an array is preserved after removing an item.

* Merge upstream

* Fix crash

* Add VS projects files and fix mixed tab/spaces

* Remove erroring on "json_free"

* Add comments to "json.inc" file

* Remove overloaded operators

* Use of "override" keyword where needed

* Fix parameter's name

modules/json/AMBuilder

@@ -0,0 +1,24 @@
+# vim: set sts=2 ts=8 sw=2 tw=99 et ft=python:
+import os.path
+
+binary = AMXX.MetaModule(builder, 'json')
+
+binary.compiler.defines += [
+  'HAVE_STDINT_H',
+]
+
+binary.compiler.cxxincludes += [
+  os.path.join(builder.currentSourcePath, '..', '..', 'third_party', 'parson')
+]
+ 
+binary.sources = [
+  '../../public/sdk/amxxmodule.cpp',
+  '../../third_party/parson/parson.c',
+  'JsonMngr.cpp',
+  'JsonNatives.cpp',
+]
+
+if builder.target_platform == 'windows':
+  binary.sources += ['version.rc']
+  
+AMXX.modules += [builder.Add(binary)]