Changed type of BricComponent name from Name to PropKey

For auto-generated components, numeric names will have to be used in
some cases.

Also removed now unused class HasName.
Added tracking of additional source information to InputTerminal
Improved interface of Value class hierarchy

* Added override and final specifiers to classes and methods
* Removed non-templated typedPPtr() methods
* Added const to Value::valid() and Value::empty()
Made classes Name, PropVal, PropKey and PropPath final
Added override and final specifiers to methods of HasValue classes
Added override specifier to LoggingFacility methods
Added override and final specifier to main Bric classes [UNFINISHED]

Also removed unimplemented	Bric::connectInputsRecursive() and remnant
Bric::canHaveDynBrics().