Multiple assets upload implementation

[valery1707]

I think this is very usefull feature. Changes in cofiguration:

<configuration>
    ...
    <artifact>path/to/single/asset</artifact>
    <!--One fileSet to include many files-->
    <fileSet>
        <directory>path/relative/to/the/POM/where/the/resources/are/stored</directory>
        <!--Includes pattern-->
        <includes>
            <include>**/pom.*</include>
        </includes>
        <!--Excludes pattern. Excludes take priority over includes.-->
        <excludes>
            <exclude>**/log.log</exclude>
        </excludes>
    </fileSet>
    <!--Many fileSets and each can define many assets-->
    <fileSets>
        <fileSet>
            <directory>path/relative/to/the/POM/where/the/resources/are/stored</directory>
            <!--Includes pattern-->
            <includes>
                <include>**/pom.*</include>
            </includes>
            <!--Excludes pattern. Excludes take priority over includes.-->
            <excludes>
                <exclude>**/*.properties</exclude>
            </excludes>
        </fileSet>
    </fileSets>
</configuration>

Assets with same filename will be rewritten, if ${overwriteArtifact} is true, or exception will be thrown.

[valery1707]

Thanks for great plugin!