Fix MediaWrite Test to function also in non GMT+2 timezones
Add ExiftoolComponent
Fix Tests
Add option to batch read metadata, by keeping exiftool open (-stay_open option):
- faster(x7) read of metadata by keeping exiftool open until all files are readed
- per total import performance: x2.5 faster
TODO:
- add call to exitExiftool() in parent controller (before exit event) and in shutdown function
Add admin option for basic user logging ( 'IP_log' ) : username, userid, IP, path
TODO:
- make it like a statistical feature with different details.
Increase 'max_execution_time' (only for admins, only for import page) to 1 hour in order to allow importing large amount of files at once
Add browser import option:  import only sellected extensions
Add browser option to force reRead metadata, ONLY for existing media.
(exemple: for re-updating metadata after a change in phtagr metadata coding or for files updated outside phtagr, without changing any date on the file)
Fix Tests
fix admin_index display for guests
add some details to page Users/List User/Admin
Add SidecarFilterComponent.
Add chain icon for sidecar file types.

Add option to read/write from/to xmp sidecar (filename.xmp) file for images.
When writing media to file, sidecar will be created  if missing.
Any change will be saved to sidecar in XMP format.
TODO: add sidecar to zip when downloading.

I really don't like changing my original files (for exemple: even exiftool repository package for ubuntu is very old and is messing-up CFA Pattern  by writing as list instead of structure). Last version of exiftool for PERL(and perl) should be installed on ubuntu.
Fix insufficient memory issue when importing thousands of files.

Until now around 23 kb were used for each file by storing $media in $result (with standard 128MB PHP memory and 18 MB used by the program, only 110 were available for storing result array, sufficient for maximum 4780 files).
Now with only 0.3kb used for each file in result, memory should be enough for over 300.000 files.
Add functionality for logging import speed and memory utilized:
- total time and memory;
- average time and memory;
- time and memory needed for last file.
Improve import and export of tags (from/to both IPTC:keywords and XMP:subject).
Improve new Exiftool component

- Use Exiftool as component
- Simplefy pipes of Exiftool component
- Fix close process pipes in shutdown event (also in tests)
- Fix priority of XMP sidecar filter
- Fix upload with plupload
- Improve sidecar filter with file cache per directory
Variable and method renameing
Removed unused methods
Fix blocking of phtagr caused by keeping exiftool open.

Shutdown function from ExiftoolComp is not called in case of BrowserC. redirect.
Fix tests by adding Exiftool exit.
Add missing fields to exiftool list of retrieved fileds.
Add version check for Exiftool component

The version check enabled -config option starting from version 7.98
and -stay_open option starting from verion 8.42
Use shutdown event for Exiftool instead of direct call

tearDown() is called on error in tests. Controller::shutdownProcess() triggers
shutdown() call for all components. Therefore, it is sufficient to close open
pipes in Exiftool in the shutdown method.
Decrease loop waiting time to create new tmp file;
Improve clearMetaData speed by using exiftool -stay_open argument.
Delete unutilised clearMetaData from other files.
Improve logging to 'import_memory_speed.log'
Fix reading video files via exiftool

- VideoFilterComponent::_readVideoFormat() to read meta data from
  ExiftoolComponent and process the meta within the
  VideoFilterComponent::_readExiftool()
- Set stdout and stderr of exiftool pipes to blocking on init procedure
- Add exiftool option -overwrite_original for meta data export which
  functionality was done by phtagr itself.
- Add ExiftoolComponent::isEnabled() function to check weather exiftool is
  available or not
Comments and function access modifier changes