[GSoC][Patch] Automatic Mode Detection V1

Dear all,

This is my first patch of my GSoC project, query tool automatic mode detection.

In this patch, the initial (basic) version of the project is implemented. In this version, query resultsets are updatable if and only if:

- All the columns belong to a single table

- No duplicate columns are available

- All the primary keys of the table are available

Inserts, updates and deletes work automatically when the resultset is updatable.

The 'save' button in the query tool works automatically to save the changes in the resultset if the query is the updatable, and saves the query to a file otherwise. The 'save as' button stays as is.

I will work on improving and adding features to this version throughout my work during the summer according to what has the highest priorities (supporting duplicate columns or columns produced by functions or aggregations as read-only columns in the results seems like a good next move).

Please give me your feedback of the changes I made, and any hints or comments that will improve my code in any aspect.

I also have a couple of questions,

- Should the save button in the query tool work the way I am using it now? or should there be a new dedicated button for saving the query to a file?

- What documentations or unit tests should I write? any guidelines here would be appreciated.

Thanks a lot!