verilog: Support for Verilog 2001 port declaration

Starting from version 2001, the Verilog standard allows module
declaration in the following format:

module module_name (
    input wire a,
    output reg b
);

This patch adds a check to confirm if the name of the port is not a
keyword, guaranteeing that the port net type is not added as a port by
mistake.

Note: when using this format only the port declaration is listed with
the assumption that the respective net type is not important. Although
this concept true in my workflow, this might not be so in all situations
and is open to further discussion.
verilog: Add scope information extraction

Add tokenInfo structure and required helper functions to implement a
push/pop stack containing the current context of the tags being found.