Release/1.1.0 (#91)

* Query: non-functional clean-up.

This change normalizes a bunch of variable names, docs, punctuation, and aliased functions (like join vs implode) - consistency!

* Query: add copy_item() method. (#89)

This change introduces a way to allow for copying an existing item/Row in the database, with the option to override that data via the $data parameter.

The goal of including this method as a low-level API is to reduce the amount of code necessary to support this action higher up in the application layer (global functions, etc...)

* Table: fix format of query inside index_exists(). (#90)

This change prevents quotes around the $column value by not preparing it, and also by making sure its value is only 1 of 2 intended columns: Key_name and Column_name.

This fixes incorrectly generated SQL, allowing this method to function as intended instead of incorrectly returning no results.

Props @ashleyfae. Fixes #87.