Management of writable files within tests

	This provides an abstraction for files generated by the test.
	
	The files are stored in the standard osgi instance area (argument -data <my data area> to an OSGi launch, default is a ./data directory in the execution directory) under a ${osgi.instance.area}/executionResources directory.
	
	A subdirectory is created for each execution, thus avoiding that the files override each other.
	
	The format of this directory is yyyyMMdd_HHmmss_<execution context uuid>
	
	In order to use it:
	
	[[1]] First declare a ResourcesManager in your application context. It has to reference the SLC Execution Context (always available):
	    
+-------------------------------+
<bean id="basic.resourcesManager" parent="slcTemplate.fileResources">
    <property name="executionContext" ref="executionContext" />
</bean>
+-------------------------------+
	
	[[1]] Then you can retrieve Spring Resources via a call to this manager. For example (it could also be an inner bean):
	
+-------------------------------+
<bean id="basic.writeTo" factory-bean="basic.resourcesManager"
    factory-method="getWritableResource" scope="execution">
    <constructor-arg value="subdir/writeTo" />
    <aop:scoped-proxy />
</bean>
+-------------------------------+
	
	The "constructor argument" (just a Spring notation in this case) is a relative path that you want to give to this file.
	Within a given execution, repeated calls on the manager with the same relative path will always point to the same file.
	
	[[1]] Then simply use this standard Spring Resource where required:
	
+-------------------------------+
<bean parent="task.echo">
    <property name="message" value="DATA" />
    <property name="writeTo" ref="basic.writeTo" />
</bean>
+-------------------------------+
	
	Underlying calls to the getFile() method of this resource won't fail (since they are writable).

Factory bean for execution resources

	Here is an enhancement to declare execution resources:
	
+-------------------------------+
<bean id="executionResources.placeholderPass" parent="slcTemplate.simpleFlow">
    <constructor-arg ref="executionResources.spec" />
    <property name="executables">
        <list>
            <bean parent="task.echo">
                <property name="message" value="DATA" />
                <property name="writeTo">
                    <bean parent="slcTemplate.resourcesFactoryBean" scope="execution">
                        <property name="executionResources" ref="executionResources" />
                        <property name="relativePath" value="subdir/@{var}" />
                        <aop:scoped-proxy />
                    </bean>
                </property>
            </bean>
        </list>
    </property>
</bean>
+-------------------------------+
	
	This allows to pass @{} execution parameters.
	
	The other form WON'T WORK if you try to passe @{} in the constructor-arg tag (but still works if the relative path does not contain a @{}):
	
+-------------------------------+
<bean id="executionResources.placeholderFail" parent="slcTemplate.simpleFlow">
    <constructor-arg ref="executionResources.spec" />
    <property name="executables">
        <list>
            <bean parent="task.echo">
                <property name="message" value="DATA" />
                <property name="writeTo">
                    <bean factory-bean="executionResources" factory-method="getWritableResource"
                        scope="execution">
                        <constructor-arg value="subdir/@{var}" />
                        <aop:scoped-proxy />
                    </bean>
                </property>
            </bean>
        </list>
    </property>
</bean>
+-------------------------------+