Add a new mode: 'replace'

[hgschmie]

In this mode, a given value from the pom will be replaced with a value
from the "replacementValues" configuration.

This allows e.g. to override the packaging of an artifact with a fixed
value.

e.g. the following configuration repackages the POM for a jar file as
a pom artifact with a different artifact id:

<configuration>
    <pomElements>
        <packaging>replace</packaging>
        <artifactId>replace</artifactId>
    </pomElements>
    <replacementValues>
        <packaging>pom</packaging>
        <artifactId>@project.artifactId@-it-parent</artifactId>
    </replacementValues>
</configuration>

[slawekjaranowski]

As usual IT should be added.

[slawekjaranowski]

Also documentation will be appreciated.

Yes - I don't see any documentation for pomElements - so it can be first step for replace mode