WIP: delayed printing

Use queue of tokens, implement lookahead when needed
Move reading int argument to 'get_int_arg'
Add `read_conf_file()` - read file specified in param

Code (mostly) moved out from `read_configs()`
Improve comments
Use descriptive names for return codes
Add option to read configs from specified file

Previously only default name/location could've been used
Fix file name 'conf_file_create.h'

Makefile was not adjusted, when file names were changed earlier
From TODO list remove 'CASE' expressions

Alraedy implemented