[FIX] matrix_base: Compiler warnings for unsigned int to size_t cast.
[FIX] matrix_base: Compiler warnings for unsigned int to size_t cast.

xenigmax/seqan,xenigmax/seqan,bestrauc/seqan,hannespetur/SeqAnHTS,xenigmax/seqan,bestrauc/seqan,xenigmax/seqan,hannespetur/SeqAnHTS,bestrauc/seqan,hannespetur/SeqAnHTS,xenigmax/seqan,hannespetur/SeqAnHTS,hannespetur/SeqAnHTS,bestrauc/seqan,bestrauc/seqan,xenigmax/seqan,hannespetur/SeqAnHTS,xenigmax/seqan,bestrauc/seqan,hannespetur/SeqAnHTS,hannespetur/SeqAnHTS,hannespetur/SeqAnHTS,bestrauc/seqan,xenigmax/seqan,bestrauc/seqan