copy of connector-c-sql branch

CMakeLists.txt

client/CMakeLists.txt

client/tarantool/CMakeLists.txt

client/tarantool/tnt.c

client/tarantool/tnt_admin.c

client/tarantool/tnt_admin.h

connector/c/CMakeLists.txt

connector/c/sql/CMakeLists.txt

connector/c/sql/tnt_lex.c

connector/c/sql/tnt_lex.h

connector/c/sql/tnt_sql.c

connector/c/sql/tnt_sql.h

connector/c/sql/tnt_utf8.c

connector/c/sql/tnt_utf8.h

test/CMakeLists.txt

test/box/connector.c