Use strncmp to avoid buffer overflow
Use strncmp to avoid buffer overflow

Closed: #241

chewing/libchewing,yan12125/libchewing,hiunnhue/libchewing,yan12125/libchewing,chewing/libchewing,hiunnhue/libchewing,cwlin/libchewing,cwlin/libchewing,chewing/libchewing,cwlin/libchewing,hiunnhue/libchewing,hiunnhue/libchewing,chewing/libchewing,cwlin/libchewing,yan12125/libchewing,yan12125/libchewing,hiunnhue/libchewing,cwlin/libchewing