enable create table in sqlite3

Signed-off-by: Kenji Ohtsuka <kok.fdcm@gmail.com>
Merge pull request #1803 from KenjiOhtsuka/1.8/feature/create_table_in_sqlite

enable create table in sqlite3
modify comments

Signed-off-by: Kenji Ohtsuka <kok.fdcm@gmail.com>
Merge branch '1.8/develop' into 1.8/feature/add_missing_comments
Merge pull request #1805 from KenjiOhtsuka/1.8/feature/add_missing_comments

added missing comments and modify existing comments
Merge branch '1.8/develop' of https://github.com/fuel/core into 1.8/develop