appengine:devserver - excluding directories from triggering reload

[GoogleCodeExporter]

Talking about version 1.9.1 and goal mvn appengine:devserver

The automatic reload mechanism of the devserver now works really nice. Whenever 
the IDE compiles a file the devserver picks up changes and restarts the 
devserver. 

Moreover - we did not yet get any PermGen exceptions. Really nice work.

However, there is one thing that would further improve the way we work with the 
appengine: Having the ability to exclude certain directories from triggering 
the reload mechanism. 

Something like that exists for instance in the jetty-maven-pugin via  

<scanTargetPatterns>
            <scanTargetPattern>
              <directory>src/other-resources</directory>
              <includes>
                <include>**/*.xml</include>
                <include>**/*.properties</include>
              </includes>
              <excludes>
                <exclude>**/myspecial.xml</exclude>
                <exclude>**/myspecial.properties</exclude>
              </excludes>
            </scanTargetPattern>

or in ninja-maven-plugin via

    <configuration>
        <useDefaultExcludes>true</useDefaultExcludes>
        <excludes>
            <exclude>(.*)png$</exclude>
        </excludes>

Especially when developing heavily javascript based applications this would 
come in handy and would speed up development significantly (reloading the 
devserver still takes some seconds).

Original issue reported on code.google.com by raphael....@gmail.com on 23 Mar 2014 at 11:59