Add warnings flag during build.
Some cleanups:
1. Changes to fix warnings during compilation.
2. Have partition_tasks return the end file offset of the last partition.
3. Remove the individual file partitions on completion.
Clean up the merge function.
Add option to specify the output file for the sorted records.
Count only the resources that will be used to run tasks when modeling the
runtime.
Add feature that samples the execution environment by sorting two small
partitions.
Organize the code for the environment sampling.
Add a function that waits for the completion of the partitioned tasks.