fix some warnings because a char was used as array index; can cuase problem when char is signed and contains values<0 (>=128); does filter work at all for 8 bit characters? can that occur?
fix some warnings because a char was used as array index; can cuase problem when char is signed and contains values<0 (>=128); does filter work at all for 8 bit characters? can that occur?

git-svn-id: 67bf12f30ddf2081c31403e0b02b2123541f1680@3311 08b3d480-bf2c-0410-a26f-811ee3361c24

kongr45gpen/bzflag,adamsdadakaeti/bzflag,adamsdadakaeti/bzflag,kongr45gpen/bzflag,adamsdadakaeti/bzflag,adamsdadakaeti/bzflag,adamsdadakaeti/bzflag,kongr45gpen/bzflag,adamsdadakaeti/bzflag,khonkhortisan/bzflag,kongr45gpen/bzflag,khonkhortisan/bzflag,khonkhortisan/bzflag,khonkhortisan/bzflag,kongr45gpen/bzflag,kongr45gpen/bzflag,khonkhortisan/bzflag,kongr45gpen/bzflag,khonkhortisan/bzflag,adamsdadakaeti/bzflag,khonkhortisan/bzflag,kongr45gpen/bzflag