parser: Pass CPP path from CMake

The parser shouldn't be trying to construct the CPP binary name from
environment variables.

parser: check options has queries attrib

Added a check for the queries option in the parser. This would
otherwise throw an exception if options doesn't have the queries
attribute.

camkes/parser: add query to camkes ADL

This commit adds a new feature called a query. A query appears in the
ADL on the RHS of a setting in the configuration section of the ADL, eg:

configuration {
component.blah = query()
}

queries takes comma separated parameters that can be any literal (numeric_expr |
multi_string | list | dict).

Queries are parsed in a new parsing stage between stage7 and stage8.

Fix whitespace

- remove trailing whitespace
- remove duplicate blank lines
- remote blank lines at end of file

Fix licenses

Allow old style N-1 connection syntax

In previous versions of CAmkES, N-1 connections could be declared by
using multiple connection statements with interfaces in common. CAmkES
next removed support for this, replacing it with connection statements
that allow multiple interfaces on either side. This proved too
restrictive, as it made it impossible to connect both external and
internal interfaces to an interface exposed by a hierarchical component.

This change adds back limited support for the old syntax. An interface
may appear in multiple connections, provided that:
- it is on the same side (to/from) of each connection
- the connector type of each connection is the same
- it is the only interface on its side of each connection

Refactored parser init commit.