LMSQL: Connect and perform MySQL database queries

This class can connect and perform MySQL database queries.

It can connect to a MySQL database using the PDO extension.

The class can also perform common queries taking some parameters like:

- Get data from a table with a condition clause, limit, order and custom sorting by field
- Get one row from a table
- Insert data into a table
- Update table rows
- Delete table rows
- Get the total number of table rows
- Get the last inserted table identifier
- Search in all fields
- Search in specific fields
- Show tables of current database
- Show columns of a table
- Execute a custom SQL query