Purpose
-------
A "statefile" would contain recorded information about the state,
including all userdata, etc. so that statistics calculation could
be "continued" from that point.

Could be specified with option, e.g. "fisg -s paska.state" or
within the configuration file.

Every time FISG would be ran, it'd read and check this file to
retrieve the previous state, and then based on the given input files
check if something needs to be updated. After update, state would
be recorded into the statefile again.

Format
------
First, lines with filenames and data to check changes against.
Every line of this type will start with a pipe "|" and is
formatted as follows:

|/path/filename|last changed date|

State data would then follow

!genericstatedata
:user:info:something:
:user:info:something:
:user:info:something:
:user:info:something:
...
...
...


How would it work?
------------------
1) Read statefile in
2) Go through given input files:
   - If a new file, parse ->
   - If old file: Has the file been "touched" (date changed)? yes -> parse
3) Save state