[FIX] Fixing writing of comment header in SAM format.
[FIX] Fixing reading of first record after @CO header in SAM.

Before this patch, the readRecord() function skips the first record.
Merge pull request #170 from holtgrewe/hotfix/sam_read_after_comment_header

[FIX] Fixing reading of first record after @CO header in SAM.
Merge pull request #169 from holtgrewe/fix_sam_write_co

[FIX] Fixing writing of comment header in SAM format.