Upgrading to 2.4.0 fails due to a breaking change with com.mchange.c3p0 dependency

[mossinipaolo]

Upgrading to version 2.4.0 introduces a breaking change due to the c3p0 dependency being set to provided scope. As a result, applications that relied on com.mchange.v2.c3p0.ComboPooledDataSource without explicitly declaring the dependency now fail with the following runtime error:

java.lang.ClassNotFoundException: com.mchange.v2.c3p0.ComboPooledDataSource

A minor version upgrade should not introduce breaking changes. If a dependency scope change leads to runtime failures, it should warrant a major version bump.

The change in dependency scope causes applications to fail unless they explicitly declare c3p0 as a dependency. This unexpected change breaks backward compatibility.

[xjokerabab]

The following c3p0 package can be added to temporarily solve the problem

    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.5</version>
    </dependency>

[jhouserizer]

relates to #1345

[jhouserizer]

Context: .... this was a purposeful change because people who do not use DB-backed quartz (e.g. use RAMJobStore) complain about the dependency being pulled in. Needs better documented.