Resource filtering fix

[abelsromero]

This PR includes the fixes discussed in issue #187.
The required libraries to enable filtering have been added and now it's possible to use it. Hovewer, this is not exposed in the documentation.

Here is the list of changes in this PR:

• Updated README to align with maven-resource-plugin configuration and explain the supported options. Note that using only without works also, I guess it's my gradle side that preffers it.
• Added integration test for property filtering (a.k.a. replacing). Even if it's not officially supported, that way we have an example if someone wants to use it and asks about it.
• Fixed an issue: when defining custom file extensions in sourceDocumentExtension, these were also copied. Now they are excluded.

[coveralls]

Coverage decreased (-0.4%) to 59.56% when pulling 3579c9d on abelsromero:resource_filtering_fix into a9c3f7b on asciidoctor:master.

[coveralls]

Coverage increased (+0.3%) to 60.212% when pulling 3579c9d on abelsromero:resource_filtering_fix into a9c3f7b on asciidoctor:master.

[abelsromero]

comments?

[mojavelinux]

I don't think this comment is correct. The resources aren't copied to the source directory but rather the output directory, correct?

[abelsromero]

Reading it again I think that the overall section is not clear. I propose the next text.

• Replaced first line telling that if resources are not set all resources insidesourceDirectoryare copied
• Corrected descriptions for and

resources:: list of resource files to copy to the output directory (e.g., images, css). The configuration follows the same patterns as the `maven-resources-plugin`. If not set, all resources inside `sourceDirectory` are copied
+
[source, xml]
----
    <resources>
        <resource>
            <!-- (Mandatory) Directory to copy from. Paths are relative to maven's ${baseDir} -->
            <directory>DIRECTORY</directory>
            <!-- (Optional) Directory to copy to. By default uses the option `outputDirectory` -->
            <targetPath>OUTPUT_DIR</targetPath>
            <!-- (Optional) NOTE: SVN, GIT and other version control files are excluded by default, there's no need to add them -->
            <excludes>
                <exclude>**/.txt</exclude>
            </excludes>
            <!-- (Optional) If not set, includes all files but default exceptions mentioned -->
            <includes>
                <include>**/*.jpg</include>
                <include>**/*.gif</include>
            </includes>
        </resource>
        <resource>
                ...
    <resources>
----

[abelsromero]

Sorry to ask, but what do you think of the proposals?

[coveralls]

Coverage increased (+0.3%) to 60.212% when pulling 8afe558 on abelsromero:resource_filtering_fix into a9c3f7b on asciidoctor:master.

[abelsromero]

@mojavelinux I am a bit confused, I see the 'thumbs' up in the issue, but since it does not show the dat I am not sure if this has been review.

Is it good to merge?

[mojavelinux]

I didn't think about the fact that the reaction icon doesn't show the date. When I'm giving a 👍 to say "proceed with merge" I'll use a comment instead. In this case, I was giving the thumbs up to merge.

[abelsromero]

Good to know I did not screw up 😄

[mojavelinux]

Not at all. You're doing fantastic, both on the code and communicating. We're so lucky to have you at the lead!