Refactored alias and function code into smaller units of functionality.

* _print_aliases calls _print_alias to break work into smaller tasks.
* _print_functions calls _print_function to break work into smaller tasks.
Enhanced "dots" function with the 's' search option for easily searching for an alias/function.

* Refactored the finding function labels and descriptions into private methods.
* Added private methods for finding aliases, functions, and commands (i.e. combination of alias and function).
Fixed function label comments to use "Label:" instead of "Name:" for label definitions.