Improv/karaf2.3.5

This pull request introduce four major upgrades to our system:

* Karaf 2.3.5 (instead of Servicemix 4.5.2)
  * Spring 3.2.4 (instead of 3.0.7)
  * Spring Security 3.1.5 (instead of 3.0.8)
* PaxExam 3.4.0 (instead of 2.3.1)
  * Junit 4.11 (instead of 4.10)
* CXF 2.7.10 (instead of 2.7.7)

Here's a short list of what this changed implied:

### Karaf 2.3.5

- Upgrade Spring was required.
- Karaf 2.3.5 introduces Apache Aries 1.0.1. There's a bug not solved yet which could be skipped via a work-around (comments on features.xml of opennaas.core).
- Property-placeholder must contain a default property value in order to avoid service registration and unregistration on startup. It was not enough in some cases, so Isart had to change the strategy to avoid this relad system. 
- We can delay the CLI prompt, so the user can't write any command until all bundles are started :)

### Spring / Spring security

- Some depracated classes and attributes were modified. Update was trivial.

### Junit 

- Classes of package junit.framework are depracated, so they were replaced by the ones offered in org.junit 
- There was a problem with the @BeforeClass annotation and the static attributed initialized in them. After studying viability, they were replaced by @Before  annotation.

### Pax-Exam

- New Karaf-container provided by PaxExam, replacing and deprecating the one provided by openengsb.labs
- Upgrade from junit 4.10 to 4.11 was required.
- Modify all integration tests with new semantic.


In following pull requests, more libraries would be upgraded.

Finally, a new option had to be added to itests, since the karaf.delay.shell option and pax-exam doesn't look to be very close friends...