[ADD]hr_timesheet_sheet : Added day view in hr_timesheet_sheet and improved timesheet widget, added single widget Timesheet which having two modes day mode and week mode.
-Improved week widget's design, used bootstrap.
-Day mode having block of 7 days and having pagination for next days, at a time single day is active, provide navigation when one click on header of particular day.
-one can select all accounts in single day, once account in particular day is selected it will not be fetched in name_search of same day(added domain based on day).
-Created two internal widgets which actually access same data, so that data remains synchronized in both mode, day and week.
-Allow edition of description.
-Add feature of clock timer to enter timesheet.