Improve Phing's ability to work as an "embedded" process

[hans]

Currently Phing does some things that make it impossible to invoke it within other applications. For example:

1. Phing currently calls exit() in its shutdown() method.
2. The phing.php script does a bit more setup/teardown than it should.
3. Exceptions are being printed to STDERR by Phing class currently instead of bubbling up to calling phing.php script.
4. Resource paths are only resolved relative to include_path, which shouldn't have to include the phing.home dir.
5. INI settings that Phing changes are not restored in shutdown phase.
6. Trailing spaces may prevent inclusion in web apps ("output already started") errors

[hans]

(In [322]) Refs #201 - (IN PROGRESS!) Checking in in-progress work to improve Phing's ability to be embedded in other applications. ERROR HANDLING HAS NOT BEEN FULLY TESTED WITH THIS CHANGESET.

[hans]

(In [323]) Refs #201 - Added improved support for arg parsing in Phing::execute() as well as better error handling between phing.php CLI script and Phing class.

[hans]

(In [325]) Refs #201 - Removed closing ?> from class files.

[hans]

(In [326]) Refs #201 - Fixing argument parsing from bug introduced in [323]

[hans]

(In [327]) Refs #201 - Fixing another (!) argument parsing bug introduced in [326]

[hans]

(In [327]) Refs #201 - Fixing another (!) argument parsing bug introduced in [326]

[hans]

(In [330]) Refs #201 - Fixing support for additional properties

[hans]

(In [330]) Refs #201 - Fixing support for additional properties

[hans]

(In [331]) Refs #201 - Changing Phing::start() API to accept array of properties instead of Properties object.

[hans]

Am closing. As of r331, this system is working very well embedded within other PHP scripts. The fact that all errors bubble through as exceptions and no exit() is performed by Phing class, is a definite improvement.