Added method to get a column from a table node.

Fixed typo that added 1 to the number of columns required

Fixed coding style

Removed all unnessacery usage of double quoting then escaping.

Changed selection to be more readable

Added nice error message when you try to get a none existant column from the table

Revert "Added nice error message when you try to get a none existant column from the table"

This reverts commit 5f15c3efaefe9b4aa6b1119c65180ffe6c1201d8.

This will be done in the constructor, in a later PR
Merge branch 'master' of github.com:PurpleBooth/Gherkin