Sorted Vector & binary search functionality.

Bug: 16659276
Tested: on Linux & Windows.

Change-Id: Ie7a73810345fad4cf0a3ad03dfaa5464e3ed5ac8

docs/html/md__schemas.html

@@ -146,6 +146,7 @@ root_type Monster;
 <li><code>force_align: size</code> (on a struct): force the alignment of this struct to be something higher than what it is naturally aligned to. Causes these structs to be aligned to that amount inside a buffer, IF that buffer is allocated with that alignment (which is not necessarily the case for buffers accessed directly inside a <code>FlatBufferBuilder</code>).</li>
 <li><code>bit_flags</code> (on an enum): the values of this field indicate bits, meaning that any value N specified in the schema will end up representing 1&lt;&lt;N, or if you don't specify values at all, you'll get the sequence 1, 2, 4, 8, ...</li>
 <li><code>nested_flatbuffer: "table_name"</code> (on a field): this indicates that the field (which must be a vector of ubyte) contains flatbuffer data, for which the root type is given by <code>table_name</code>. The generated code will then produce a convenient accessor for the nested FlatBuffer.</li>
+<li><code>key</code> (on a field): this field is meant to be used as a key when sorting a vector of the type of table it sits in. Can be used for in-place binary search.</li>
 </ul>
 <h2>JSON Parsing</h2>
 <p>The same parser that parses the schema declarations above is also able to parse JSON objects that conform to this schema. So, unlike other JSON parsers, this parser is strongly typed, and parses directly into a FlatBuffer (see the compiler documentation on how to do this from the command line, or the C++ documentation on how to do this at runtime).</p>