Moved input folder to input/current/, fixed cross-compatibility bug

the project now compiles on Visual Studio 2010
pictogram extraction: additional cropping at the right & bottom of the images
feature extraction: included Pierre's modifications on preprocessing
feature extraction: don't write pictograms that cause an exception

this implied using temporary ostringstreams for the feature extractors
feature extraction debug: added image dumping during processing
pictogram extraction: increase cropping to 10px on the right and bottom
feature extraction debug: corrected dumping the normalized image
corrected feature extraction normalization + changed directories
feature extraction: fixed bug when parsing a blank image

blank images are now correctly ignored and their filename dumped to feature_errors.txt
pictogram extraction: increased cropping