move to_filename into the Utils module
move tasks into Task

	modified:   modules/Pipelines/lib/CoGe/Pipelines/SNP/Samtools.pm
	renamed:    modules/Pipelines/lib/CoGe/Pipelines/SNP/Samtools.pm -> modules/Pipelines/lib/CoGe/Pipelines/SNP/Tasks.pm
add annotation support to load_experiment
add platypus pipeline