Now ttail is able to sort logfiles given as arguement.
The sort function _ttail_file_sort place files with no valid date to the
end of the file list and is able to detect if some files overlaps.

No tests written...

Not 100% sur of implementation. And the feature seems a bit useless..

Adds the option -P --permissive.

Starts implementation for logfiles.

Now -P flag make ttail handle invalid files. When invalid file given the
minmax function set the file pointer and the minmax array to NULL.

May introduce bugs if the binary search function does not handles "holes"
in fp array or in minmax array...

Not done for stdin

Segfault was thrown when no files were found with matching date

Now an error is triggered if date-min > date-max
Bugfix on date-max searching (on multiple loglines with a date == date-max)

Add some perror calls

Deleted old argument struct tm* from search function (now using infos
stored in ttail_t.session )

Now we have a running minimal ttail :
src/ttail -d "Mar 6 00:29" -f '%B%n%d %H:%M' -l tests/samples/1.log -l tests/samples/1.1.log

Testing ttail_search_closest_files() on multiple files

untested

Set some function inlune and implement an utility function
for file searching functions.

Telling if the logfile array is sorted

The getline wrapper will allow to use getline without calling malloc
and free all the time