What steps will reproduce the problem? 1. Try to load table structure with column named length 2. Get uncaught exception RangeError: invalid array length

What version of the product are you using? On what operating system? 0.1, Mozilla Firefox 31.0, linux

I looked at the code for columns manipulation and found out that Arrays for columns used as associative containers, so we can replace Array with plain objects without any harm. Patch attached.