Phing Strict Build Mode

[utsavhanda]

Phing build would support a 'Strict' mode, which indicates to consider a warning as an error and raises a buildException to abort the build process.

Ticket
http://www.phing.info/trac/ticket/918

Specs
Phing build would support a 'Strict' mode, with the default value as Off (to enable backward compatibility until complete future migration). The 'strict' mode, when enabled, considers all the warnings (which are raised with "MSG_WARN" level) as an error, and raises a buildException to abort the build process.

This pull request adds the following functionalities:

1. The Project tag supports new attribute - strict (boolean), indicating the build process mode.

2. The Phing command-line utility would support two new parameters:
   -strict runs build in strict mode, considering a warning as error
   -no-strict runs build normally. (overrides build file attribute)

3. The command-line switches over-rides the 'Build File' "Project::Strict" attribute information.
   A sample target which builds in 'strict' mode:

<project name="PhingDev" basedir="./" default="help" strict="true" >

<property name="build.dir"  value="./" override="false" />

<!-- Target: HelloWorld -->
 <target name="helloworld">
   <echo msg="Hello, World" />
   <warn msg="${notdefined}" />
</target>

</project>

4. The documentation resources have been updated with the attribute information.

I understand, that the current Phing implementation does not consider the 'warnings' as a separate entity, but part of LogLevel. Therefore, currently, this implementation would have limited capability. But considering this as a starting point, we can utilize the future approach designing.

Legacy PR
#159

Thanks,
Utsav

[mrook]

References #554