merge revision(s) 32578,33401,33403,33404,33531,33655,33679,33809,33900,33965,34067,34069,34087,34328,34330,34527,34772,34783,34839,34914,34953,34954,35153: [Backport #6212]

	* ext/psych/lib/psych.rb: updating version to match gem
	* ext/psych/psych.gemspec: ditto
	* ext/psych/lib/psych/visitors/to_ruby.rb: fixing deprecation warning

	* ext/psych/lib/psych.rb: define a new BadAlias error class.

	* ext/psych/lib/psych/visitors/to_ruby.rb: raise an exception when
	  deserializing an alias that does not exist.

	* test/psych/test_merge_keys.rb: corresponding test.

	* ext/psych/lib/psych.rb (load, parse): stop parsing or loading after
	  the first document has been parsed.

	* test/psych/test_stream.rb: pertinent tests.

	* ext/psych/lib/psych.rb (parse_stream, load_stream): if a block is
	  given, documents will be yielded to the block as they are parsed.
	  [ruby-core:42404] [Bug #5978]

	* ext/psych/lib/psych/handlers/document_stream.rb: add a handler that
	  yields documents as they are parsed

	* test/psych/test_stream.rb: corresponding tests.

	* ext/psych/lib/psych/core_ext.rb: only extend Kernel if IRB is loaded
	  in order to stop method pollution.

	* ext/psych/lib/psych.rb: default open YAML files with utf8 external
	  encoding. [ruby-core:42967]
	* test/psych/test_tainted.rb: ditto

	* ext/psych/parser.c: prevent a memory leak by protecting calls to
	  handler callbacks.
	* test/psych/test_parser.rb: test to demonstrate leak.

	* ext/psych/parser.c: set parser encoding based on the YAML input
	  rather than user configuration.
	* test/psych/test_encoding.rb: corresponding tests.
	* test/psych/test_parser.rb: ditto
	* test/psych/test_tainted.rb: ditto

	* ext/psych/parser.c: removed external encoding setter, allow parser
	  to be reused.
	* ext/psych/lib/psych/parser.rb: added external encoding setter.
	* test/psych/test_parser.rb: test parser reuse

	* ext/psych/lib/psych/visitors/to_ruby.rb: Added support for loading
	  subclasses of String with ivars
	* ext/psych/lib/psych/visitors/yaml_tree.rb: Added support for dumping
	  subclasses of String with ivars
	* test/psych/test_string.rb: corresponding tests

	* ext/psych/lib/psych/visitors/to_ruby.rb: Added ability to load array
	  subclasses with ivars.
	* ext/psych/lib/psych/visitors/yaml_tree.rb: Added ability to dump
	  array subclasses with ivars.
	* test/psych/test_array.rb: corresponding tests

	* ext/psych/emitter.c: fixing clang warnings. Thanks Joey!

	* ext/psych/lib/psych/visitors/to_ruby.rb: BigDecimals can be restored
	  from YAML.
	* ext/psych/lib/psych/visitors/yaml_tree.rb: BigDecimals can be dumped
	  to YAML.
	* test/psych/test_numeric.rb: tests for BigDecimal serialization

	* ext/psych/lib/psych/scalar_scanner.rb: Strings that look like dates
	  should be treated as strings and not dates.

	* test/psych/test_scalar_scanner.rb: corresponding tests.

	* ext/psych/lib/psych.rb (module Psych): parse and load methods take
	  an optional file name that is used when raising Psych::SyntaxError
	  exceptions
	* ext/psych/lib/psych/syntax_error.rb (module Psych): allow nil file
	  names and handle nil file names in the exception message
	* test/psych/test_exception.rb (module Psych): Tests for changes.

	* ext/psych/parser.c (parse): parse method can take an option file
	  name for use in exception messages.
	* test/psych/test_parser.rb: corresponding tests.

	* ext/psych/lib/psych.rb: remove autoload from psych
	* ext/psych/lib/psych/json.rb: ditto

	* ext/psych/lib/psych/tree_builder.rb: dump complex numbers,
	  rationals, etc with reference ids.
	* ext/psych/lib/psych/visitors/yaml_tree.rb: ditto
	* ext/psych/lib/psych/visitors/to_ruby.rb: loading complex numbers,
	  rationals, etc with reference ids.
	* test/psych/test_object_references.rb: corresponding tests

	* ext/psych/lib/psych/scalar_scanner.rb: make sure strings that look
	  like base 60 numbers are serialized as quoted strings.
	* test/psych/test_string.rb: test for change.

	* ext/psych/parser.c: remove unused variable.

	* ext/psych/lib/psych/syntax_error.rb: Add file, line, offset, and
	  message attributes during parse failure.
	* ext/psych/parser.c: Update parser to raise exception with correct
	  values.
	* test/psych/test_exception.rb: corresponding tests.

	* ext/psych/parser.c (parse): Use context_mark for indicating error
	  line and column.

	* ext/psych/lib/psych/scalar_scanner.rb: use normal begin / rescue
	  since postfix rescue cannot receive the exception class. Thanks
	  nagachika!

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@35165 b2dd03c8-39d4-4d8f-98ff-823fe69b080e