Client: searching of a region with the number of nucleotides

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>
Client: fix a bug in IntegerWidget class

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>
Client: use 500000 instead of 4096 for regions query into "Selector.js"

Signed-off-by: Jean-François Erdelyi <jean-francois.erdelyi.1@ulaval.ca>