Added checks for file api support
Added checks for file api support

A browser without file api support, like IE9, throws an error when anything but the constructor is called, this change will fix all of the scenarios.
vulvulune/bootstrap-fileinput,anhuisunfei/bootstrap-fileinput,StoneGH/bootstrap-fileinput,yuanqixun/bootstrap-fileinput,horken-w/bootstrap-fileinput,Hkmu/bootstrap-fileinput,orcunozbay/bootstrap-fileinput,ghabib/bootstrap-fileinput,DimitriJmukhadze/bootstrap-fileinput,brees01/bootstrap-fileinput,Rizal-Afani/bootstrap-fileinput,yuanqixun/bootstrap-fileinput,pacozaa/bootstrap-fileinput,mdshakeer/bootstrap-fileinput,marceuy/bootstrap-fileinput,Hkmu/bootstrap-fileinput,saraOrg/bootstrap-fileinput,mdshakeer/bootstrap-fileinput,mehmoodulhaq/bootstrap-fileinput,kangwl/bootstrap-fileinput,brees01/bootstrap-fileinput,marceuy/bootstrap-fileinput,zhangyaoxing/bootstrap-fileinput,horken-w/bootstrap-fileinput,PrafulGoyal/bootstrap-fileinput,pravinhirmukhe/bootstrap-fileinput,ghabib/bootstrap-fileinput,Hkmu/bootstrap-fileinput,thanhluan94yt/bootstrap-fileinput,Anlim/bootstrap-fileinput,Burick/bootstrap-fileinput,xc145214/bootstrap-fileinput,xc145214/bootstrap-fileinput,thanhluan94yt/bootstrap-fileinput,pravinhirmukhe/bootstrap-fileinput,iaesaudi/bootstrap-fileinput,marcia-kubik/bootstrap-fileinput