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.