Update help on Benchmark shell.

Use newer API's for printing and formatting help.
Reformat code and remove redundant comment.
Clean up some comments and code style things.
Add missing newline.
Using constant for include path separator
added arugment parsing for BenchmarkShell, containing fix of help call
Merge pull request #80 from hiromi2424/fix-benchmark

Fix BenchmarkShell
Merge pull request #79 from jrbasso/path_separator

Using constant for include path separator