This patch provides first draft of the implementation
of the code to merge different configurations.
It is similar to the merge code that is implemented inside
the parser but different since it is not done during parsing
of one file but addresses use case when the configuration
is provided by different files that need to be merged together.

NOTE: It would make more sence to review function by function
from bottom of the patch rather than from the top.

Previous fix was not complete.
Secondary scan revealed other issues.

Previous fix was not complete. New scan revealed
potential memory leak in case of coding error.
Low severity but still a bug...

This patch makes two internal functions
resusable from different source modules.

It occured to me that one of the issues that Coverity
did not like (and I could not understand what it is
complaining about) is related to intializing the variables
in the loop.
This patch adds initialization in the loops.

All config file processing functions start with "ini_config".
The only function that does not comply is
ini_print_errors. We can't rename it since
it is a part of the current active interface.
I marked that function needs to be removed when we
remove old interface and created a copy with
the correct name. I also updated unit test accordingly.

Patch adds two functions. One tests permissions,
another validates if the file has changed or not.

Added function to detect changes to the configuration file.

I might squash this patch into one of the previous ones.

Added check access constants and the check access function.
The function is effectively copied from ini_metadata.c
The flags are copied from ini_config.h