fix of issue 142: if the type parameter is nil then make all files selectable by the user
fix of issue 142: if the type parameter is nil then make all files selectable by the user

JackLian/cocotron,guestOS/guestOS,crystax/android-vendor-cocotron,ruppmatt/cocotron,plasq/cocotron,cyclaero/cocotron,ruppmatt/cocotron,JackLian/cocotron,plasq/cocotron,cneira/cocotron,Suninus/cocotron,crystax/android-vendor-cocotron,gemu2015/cocotron-sierra,Suninus/cocotron,yuhangwang/cocotron,yuhangwang/cocotron,gemu2015/cocotron-sierra,plasq/cocotron,cjwl/cocotron,gemu2015/cocotron-sierra,JackLian/cocotron,cneira/cocotron,guestOS/guestOS,guestOS/guestOS,JackLian/cocotron,gemu2015/cocotron-sierra,cjwl/cocotron,cjwl/cocotron,Suninus/cocotron,yuhangwang/cocotron,crystax/android-vendor-cocotron,Suninus/cocotron,cneira/cocotron,cneira/cocotron,ruppmatt/cocotron,cyclaero/cocotron,cyclaero/cocotron,guestOS/guestOS,ruppmatt/cocotron,yuhangwang/cocotron,crystax/android-vendor-cocotron,cjwl/cocotron,plasq/cocotron,cyclaero/cocotron