info about layers

Found the plug-in layer-info.py, at http://registry.gimp.org/node/26317, interesting.
To make it more useful, now it can generate some information beside viewing.
The additions are:
1) viewing and adding text explanations (date, etc...), about the layer, in a layer parasite
2) plug-in auto quit if no layer or initial image
3) permitting internationalization in 'user' folders (more text)
4) only one launch at a time
5) save the info for all layers and parasites in a text file.

version 0.1:
1) an alternate way to select the active layer;
2) display two others properties: position and type;
3) harmonizing between info in display and in text file.

Make sense, fully, for 'xcf' file.

Since not able to upload here reliably, see: https://github.com/rbbrzrd/GIMP-plugins

After an extraction of the zip archive in the '.../.gimp-2.x/plug-ins' folder it should appears in GIMP
under the menu: "(Image)/Extensions/Plugins-Python/Layers/Info layers...". You can change the menu
placement the usual way or you can translate (internationalization), even in English, the menu placement is the last string.
Also about translation, there a French one in the folder 'locale' called 'info_layers.po'.

An example of the version 0.1 of the plug-in window :

[2014/07/28] Some improvements, the more visible ones being the display of 'Position' and 'Type', also
the use of colour for the 'layer-info' parasite name to indicate it's state in relation to the
text in the next field and in translation.

[2014/08/08] Add selecting active layer in the plug-in window and harmonizing window info with file one.

[2014/08/12] Corrected a serious bug, sorry for that..

[2014/08/23] Use all the width possible for the text content of 'layer-info' parasite. Some other tweaks. Please report bugs.