[FIX] added pipe support for razers

Added support to read from stdin/out via - instead of a filename or to use pipes as read files, e.g.:
```
weese@lamprey:~/seqan-dev/build/make$ bin/razers ../../core/apps/razers/example/genome.fa <(cat ../../core/apps/razers/example/reads.fa) <(cat ../../core/apps/razers/example/reads2.fa) -id -mN -o -
read1/L	0	27	F	contig1	47	73	92.593	1	-3	217
read1/R	0	27	R	contig1	237	264	96.296	1	-3	-217
read2/L	0	27	R	contig2	228	255	96.296	3	-1	-207
read2/R	0	27	F	contig2	48	75	100	3	-1	207
read3/L	0	27	F	contig2	335	362	100	2	0	221
read3/R	0	27	R	contig2	529	556	100	2	0	-221
```