Summary:
After we reached a consensus on code format, which follows exactly
Google's coding style, a natural follow-up is to have a style checker
that can handle stuffs beyond format.
Google already has a powerful style checker "cpplint.py" and,
luckily, phabricator already provides the built-in linter for it!
Next time with "arc lint" most style inconsistency will be detected
(but will not be fixed).
Also I copied cpplint.py to linters directory, which is mostly
because we may need the flexibility to make some modifications on
it for our own need.
Test Plan:
ran arc lint table/block_based_table_builder.cc to see the amazing
results.
Reviewers: haobo, sdong, igor, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D15369
