https://fedorahosted.org/sssd/ticket/1857

Discovered by coverity
The code was inaccessibile, if no key is present, the error will
occur before this check.

Added a new top level interface funtion
and a unit test for it.

This patch corrects a problem related to stats being accessed
and evaluated without being initialized.

Added unit test.

I also realized that error list processing should not be
bound to the file object.
This patch corrects that by moving the error_list and
corresponding count from file object to the config object.
Things updated by the patch:
1. The internal variables are moved from file obj to config obj.
2. The external header is updated to reflect the change
3. Functions are moved from file obj module to config obj module.
4. Parser code is updated because error validation was in
   the wrong place
5. Unit test is adjusted to get error list from the right object.

I had to adjust the copy function for the config object.
Copy function does not copy over the error list.

1.  Added definition of the parsing flags to the header.
2.  Added new argument to the parser.
3.  Added function to check the correctness of the line.
4.  Added new constants and strings for errors.
5.  Refactored function that handles spaces.
6.  Moved handle_space since it now calls handle_kvp.
7.  Updated handle_kvp to trim spaces at the beginning.
8.  Adjusted line inspection to handle any space character.
9.  Adjusted exising unit tests. Added parameter to the call.
10. Found couple places where there was a space at the end
    of the line and cleaned them.

The additional unit tests will be added in the follow up patch.

After some evaluation it became apparent that error level
and collision flags should not be a part of the fileobj
but rather passed directly to the parser function.
This way the interface is more clean and logical.
This patch:
1) Removes the error level and collision flags from
the fileobj
2) Moves validation function from ini_fileobj.c
to ini_configobj.c where it belongs.
3) Moves error level and collision flags arguments
from file open function to the parser function.
4) The internals of the file obj are cleaned
5) Validation of the arguments is moved to parser function.
6) Unit tests are updated.

Replaced sprintf in the unit test.
Defined constants for sizes and used them.
Wrpapped lines where noticed that they are longer than 80.
Added comments to the places where sprintf is still used
but it is safe to use.

Move GNU_SOUCE definition to configure.ac
Change all headers to use config.h.
Move config.h to the top.
Remove errno.h if it is not needed.