Parser

- Added alias collection methods.
Alias

- Removal of alias load/resolve code, which (1) needs a rewrite, and (2) belongs
  in the Parser.
Context

- Stubbed a ::loadAliases method to stuff the Parser with alias defs.
Parser

- Stubbed ::resolveAliases.
Context

- Stuffs parser with alias definitions, from Context::loadAliases.  This keeps
  the configuration settings apart from the Parser implementation.