Fix for 2 bugs in the fastq reader:

[wdu]

• \r\n handling may cause reading a byte past end of buffer, parser fails
• checking end-of-file condition can only be reliably done after a call to getLine() returns NULL. One particular case is that some gzip files contain empty gzip blocks at the end of the file, which can´t be predicted by the current eof() code Tested with files provided in issue #491.

This reverts commit 0ee1b3b3af1c2c890b063261b2ff55305bb220f0, "fix a regression bug of FASTQ reader"