Check return status of IO calls to prevent gcc 4.6.3 warnings
mpileup: Detect non-recoverable errors and exit with proper status
Merge branch 'fix' into calling
Merge branch 'calling' into develop
stats: Fixed off-by-one error in GCD stats which overestimated GC content by 1 part in GCD bin size
Merge branch 'calling' into develop
Merge branch 'develop' into calling