#331 Record warnings in output xena file

[Terry O'Neill]

In some cases when processing a file the plugin library used reports warnings or minor errors which do not prevent the creation of a xena output file. However these warnings may be important and should be recorded in the xena file. An example of this is the output of the ImageMagick convert utility which is currently just shown to the console and the log. The log output in this case is shown below. The file that results in this output is attached (13383_05_rotated.tif).

[Fri Nov 02 12:26:12 EST 2012] - Image Magick error/warning output for conversion:
convert: /home/toneill/Xena/XenaTestFiles/13383_05_rotated.tif: unknown field with tag 32934 (0x80a6) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/706.
convert: /home/toneill/Xena/XenaTestFiles/13383_05_rotated.tif: unknown field with tag 34821 (0x8805) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/706.
convert: /home/toneill/Xena/XenaTestFiles/13383_05_rotated.tif: unknown field with tag 37680 (0x9330) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/706.
convert: incorrect count for field "Tag 32934" (0, expecting 1); tag ignored. `/home/toneill/Xena/XenaTestFiles/13383_05_rotated.tif' @ warning/tiff.c/TIFFWarnings/706.
convert: /home/toneill/Xena/XenaTestFiles/13383_05_rotated.tif: unknown field with tag 34821 (0x8805) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/706.
[Fri Nov 02 12:26:12 EST 2012] - file:/home/toneill/Xena/XenaTestFiles/13383_05_rotated.tif successfully processed by Image Tiff Normaliser

[Terry O'Neill]