Replace all occurrences of 'infinite' with 'inDEfinite'. Accessor
methods OpenSSL::ASN1::ASN1Data#infinite_length and #infinite_length=
are kept as alias for backwards compatibility.

Improve test coverage of OpenSSL::ASN1. Add more BER encode/decode
tests, while reducing redundant assertions.

Improve the error message of the exception raised when
OpenSSL::ASN1::Primitive.new or OpenSSL::ASN1::Constructive.new is
called with one argument (which is wrong).

Fix the initial value of 'unused_bits' attribute of
OpenSSL::ASN1::BitString. The attribute must always contain an Integer
in the range 0 to 7.

Invalid values such as nil or values not in the range 0 to 7 are
silently coerced into the valid range. This behavior is confusing and
hides user bugs. Raise an exception instead if an illegal value is
specified.

Let the callers check the validity of the ASN1_TIME.

OpenSSL::ASN1::ObjectId#oid, which returns the dotted representation of
the OID, is silently truncating the result if it overflows the 128-bytes
buffer. Although it normally won't be more than 127-characters, it'd be
better to avoid. This can be done by checking the return value of
OBJ_obj2txt().

Previous releases of LibreSSL (< 2.5.1) have a bug in OBJ_obj2txt() and
it does not work if the resulting string would be larger than the
buffer. A workaround is added to the test. It should be removed when we
deprecate support for LibreSSL 2.4.

Constructed encoding can use the definite length form as well as the
indefinite length form, regardless of the tag number.

The setter method #indefinite_length= for OpenSSL::ASN1::Primitive is
undef-ed, but we can still set 'indefinite_length' to true illegally
when constructing an object with the raw OpenSSL::ASN1::ASN1Data.

Indefinite length form is not possible in primitive encoding. Raise an
exception in OpenSSL::ASN1::ASN1Data#to_der if specified.

There are actually high-tag universal types such as the time-of-day
type.

Use ossl_asn1_tag() instead of the combination of ossl_asn1_get_tag()
and NUM2INT().

Remove a mysterious behavior in Constructive#to_der: if the 'tagging'
attribute is set to :EXPLICIT and it is not an instance of universal
tag class classes, it "searches" the original tag from the first value
whose encoding is primitive.

	ary = [
	  OpenSSL::ASN1.Sequence([
	      OpenSSL::ASN1.OctetString("abc")
	  ])
	]
	cons = OpenSSL::ASN1::Constructive.new(ary, 1, :EXPLICIT)
	cons.to_der
	#=> "\xA1\x09\x24\x07\x30\x05\x04\x03\x61\x62\x63"
	#               ^
	#               This 4 comes from the OctetString

This is really confusing and nobody seems to be using this behavior.
Let's make it raise error instead.

Extract the common paths for code reduction.

Encoding with indefinite length form produces an invalid encoding if the
contents array contains an EOC object in the middle. Raise an exception
in that case.

We currently treat end-of-contents octets as a BER encoding of a value
whose tag is universal class and the number is zero, and require users
to put one in the end of 'value' array when encoding using indefinite
length form. However, the end-of-contents are just a marker indicating
the end of the contents and not really part of the contents.

Do not require users to put an EOC object in the content when encoding,
and don't produce an EOC object when decoding an encoding that uses
indefinite length form.