Fix #1956
Fix #1956

Added customSearch options
Example: http://jsfiddle.net/djhvscf/e3nk137y/4594/

horken-w/bootstrap-table,wenzhixin/bootstrap-table,djhvscf/bootstrap-table,y1170328179s/Bootstrap-table,Flounn/bootstrap-table,wenzhixin/bootstrap-table,djhvscf/bootstrap-table,djhvscf/bootstrap-table,djhvscf/bootstrap-table,CIFullCalendar/bootstrap-table,wenzhixin/bootstrap-table,danielsharvey/bootstrap-table,CIFullCalendar/bootstrap-table