C PreProcessor evaluation tools

[laerreal]

• cpptest.py, a tool that evaluates single cpp instance, system cpp or ply's cpp.
• cppevaluate.sh, an example of night running multiple cpp evaluation script based on cpptest.py.

v3

• join related commits
• outline generic common.byN (implemented using zip_longest)
• implement log_mem_usage using byN

v2

• typos

[laerreal]

v3 is ready