Clarifying usage of filename parameter
Merge pull request #38 from bredman/master

Clarifying usage of filename parameter
added insert into <cstore_table> from <another_table> support
single row inserts like insert into <table> values (...) are not
supported (ie. rejected)

a new stripe is created for each insert command. Stripe may have
empty slots after insertion depending on number of rows that are
inserted.
refreshing file list
removed commented include
reflected changes from Hadi's review
CStorePlanForeignModify no longer returns tuple metadata
some style changes
removed absolute paths from Makefile.
some more style changes in cstore_fdw.c
Merge pull request #41 from mtuncer/develop

Added support for "INSERT INTO cstore_table SELECT ...". The sub-query can have any form.

Author: @mtuncer
Code Review: @pykello