Add a config option to set the database engine to InnoDB

[NateWr]

Describe the problem you would like to solve
Some hosting environments can not change the default storage engine of the database to InnoDB because they host over software which expects MyISAM. In such scenarios, it is not possible to run recent versions of OJS which create tables using the default storage engine.

Describe the solution you'd like
Add a config option to manually specify the database engine. This config option should be added to the [database] section and commented out by default:

; Database engine
; Override this setting if you operate in a shared hosting environment and are unable to run
; OJS on the server's default database engine. 
; InnoDB is the recommended database engine for MariaDB/MySQL
; engine = InnoDB

Who is asking for this feature?
Users running OJS in a shared hosting environment.

Additional information
See the forum post.

[asmecher]

It may be possible to set the engine at the connection level, rather than needing to specify it for each table -- see: https://stackoverflow.com/questions/21380754/how-do-you-set-default-engine-for-the-schema-builder