encoding: Fix bug in TlvEncoder.writeNonNegativeInteger: value <= 0xff should be encoded using 1 byte. Refs #1926.
 CHANGELOG: Added bug 1926: Should encode non-negative integers 253 through 255 as one byte. Refs #1926.
Merge branch 'issue/1926-nonNegativeIntegers-253-through-255'. Refs #1926.
http://redmine.named-data.net/issues/1926
 Name: In Name::Component::fromNumberWithMarker, encode using TlvEncoder.writeNonNegativeInteger. This affects appendSegment and appendVersion. Refs #1833.
 CHANGELOG: Name.appendSegment, etc. now use nonNegativeInteger. Refs #1833.
 Name: In the doc for appendSegment, etc, link to the NDN naming conventions Tech Memo.
Merge branch 'master' into feross to pull in bug fix #1925 and make appendSegment, etc. encode as nonNegativeInteger.