Check if files checksum is corrupted - full requirements

[yarondbb]

1. Add global parameter (thorugh YML) for time (in Days) threshhold.
2. When application is not doing any task, check instances which their index time till current time elapsed byond the new threshhold parameter.

2.1 If files attributes has changed (or file does not exists), handle as changed file (legacy)

2.2 if file attributes are the same, then index the file and compare with existing checksum. If checksum mismatch, this file is corrupted. Do the following:
a. Write all known info in special log file (no log rotation is needed)
b. Add a state to content data file for each instance. Change the state to corupted.
c. From now on, ignore this instance (as if does not exist)