Change string concatentation to match specification

Change-Id: Iaedcfe72da7a51c86ea6cf0f4b52e38193eed3ae
Change tuple attribute selectors to have fewer special cases

Effectively, merge Ordinal and Name as special syntax in place of an
expression. This has the added bonus of making the syntax for the tuple
paired and easier to match up.

Change-Id: I178db99a2029e6e6b7fb2993afff98ac16cbdaa3
Add KWS VM documentation

Change-Id: Ibd153c42b2111071c0c8448b7aae573b9e8a7ea5