Add support for excluding hidden files in search

Signed-off-by: Kaustav Das Modak <kaustav.dasmodak@yahoo.co.in>
Refactor checkhidden method to make it work

Signed-off-by: Kaustav Das Modak <kaustav.dasmodak@yahoo.co.in>
Update information about hidden files in README

Signed-off-by: Kaustav Das Modak <kaustav.dasmodak@yahoo.co.in>