Support for python 2.5 finished!

Ok, the support for python 2.5 should be finished (surely there will be some things I'm missing, but it should be already ready for use... still, I'd currently regard it as unstable, as there were many changes in the core to make it work)

There are some things that will not go a 100% on the way python does things. Namely:

1. 'with' will always be highlighted as if they was a keyword, so, if you have code such as 'with = 1' it will be highlighted as a keyword even if you're using the grammar for python 2.4

2. If you say you're using python 2.5 in your project, it will give errors when:
- it finds the 'with' used in its old form (python would only warn you about it)
- it finds the new construct used without the 'from __future__ import with_statement' (that's the same behaviour python has)

3. Using the from __future__ import absolute_import will currently have no effect for pydev (so, it will still go after relative imports even if you specify it (unlike the ones specified before, I hope to change that in a later release).

There are some specifics to the pydev working also:
- It will now use for external files the same grammar that is specified for the actual interpreter, so, if your interpreter is for version 2.5, that's the version that it will use to do it (now and then I receive a message from people with custom interpreters, so, it is important that those interpreters have the sys.version_info return the correct info when setting up the interpreter)

- If you've specified the interpreter in a previous version, it will acknowledge it as version 2.4 even if it is actually version 2.5 (so, you have to remove and add your interpreter again).

I hope you enjoy it... it should be out in the beggining of the week... hopefully on monday or tuesday.