WatchedCDXSource Enhancements

[PsypherPunk]

As per #219, this adds optional recursion and filename filtering to the WatchedCDXSource. The defaults are equivalent to:

<property name="source">
    <bean class="org.archive.wayback.resourceindex.WatchedCDXSource">
        <property name="recursive" value="false" />
        <property name="filters">
            <list>
                <value>^.+\.cdx$</value>
            </list>
        </property>
        <property name="path" value="/wayback/cdx-index/" />
    </bean>
</property>

I had to add a equals() method for the FlatFile class as it wasn't possible to easily delete a CDXIndex otherwise—they're now considered equivalent if both are of the FlatFile class and getPath() returns the same for both.

[ibnesayeed]

I think it would be good to have a commented example config added in the CDXCollection.xml file. Also, the default path should be ${wayback.basedir}/cdx-index/ and if ${wayback.basedir} is not available where defaults are set then it should be hard-coded to /tmp/openwayback/cdx-index/ which is the default in default wayback.xml where placeholders are set.

[PsypherPunk]

While the example in the Wiki should be changed to use ${wayback.basedir}/cdx-index/, I'm averse to adding more examples to the default config. files.

The current wayback.xml is an example of overly large config. file dominated by commented-out, unused sections; I'd much prefer that the documentation was accurate and, if our users are having genuine difficultly finding examples, easier to access.

[kris-sigur]

Merged manually.