In user login:
	Fix problem, when line is longer than LINE_MAX.
	Allow to use empty (but only empty) lines in config file.

Create authentification structure with these members:
	- login
	- password
	- remoteinfo
	- remotehost
	- remoteip

Pass this structure to main_*() functions. Create plugin hierarchy,
every plugin will have its own main_*() function. Create configurable
dependencies file.