Normalize pathname for listeners, factories and root.

Pathnames used for extensions (listeners with soapui.ext.listeners, factories with soapui.ext.factories) and root (soapui.home) may contain redundant parts (e.g. `/foo/bar/..` or `/opt/soapui/bin/./ext`) which is ugly and may confuse users.

This pull request normalize these pathnames.

Example of startup messages before this pull request:
```
2013-12-05 17:50:38,682 INFO  [SoapUI] Adding [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/./ext/ibiza-soapui-utilities-1.3-SNAPSHOT.jar] to extensions classpath
2013-12-05 17:50:38,682 INFO  [SoapUI] Adding [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/./ext/ojdbc6-11.2.0.3.0.jar] to extensions classpath
2013-12-05 17:50:38,951 INFO  [DefaultSoapUICore] initialized soapui-settings from [/Users/marcpa/soapui-settings.xml]
2013-12-05 17:50:39,071 INFO  [DefaultSoapUICore] Adding listeners from [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/./listeners/demo-listeners.xml]
2013-12-05 17:50:39,880 INFO  [WorkspaceImpl] Loading workspace from [/Users/marcpa/Accovia/Soapui-workspaces/Lexo Smoke Tests Dev-workspace.xml]
2013-12-05 17:50:40,066 INFO  [DefaultSoapUICore] Defaulting to native L&F for Mac OS X
2013-12-05 17:50:40,122 INFO  [SoapUI] Used java version: 1.6.0_65
2013-12-05 17:50:41,546 INFO  [DefaultSoapUICore] Adding actions from [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/./actions/demo-actions.xml]
```

Example of startup messages with this pull request:
```
2014-01-28 11:40:39,668 INFO  [SoapUI] Adding [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/ext/ibiza-soapui-utilities-1.3-SNAPSHOT.jar] to extensions classpath
2014-01-28 11:40:39,669 INFO  [SoapUI] Adding [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/ext/ojdbc6-11.2.0.3.0.jar] to extensions classpath
2014-01-28 11:40:39,947 INFO  [DefaultSoapUICore] initialized soapui-settings from [/Users/marcpa/soapui-settings.xml]
2014-01-28 11:40:40,316 INFO  [DefaultSoapUICore] Adding listeners from [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/listeners/demo-listeners.xml]
2014-01-28 11:40:40,898 INFO  [WorkspaceImpl] Loading workspace from [/Users/marcpa/Code/soapui/soapUI-Tutorials/GettingStarrted-workspace.xml]
2014-01-28 11:40:40,969 INFO  [WsdlProject] Loaded project from [file:/Users/marcpa/Code/soapui/soapUI-Tutorials/Getting-Started-soapui-project.xml]
2014-01-28 11:40:41,602 INFO  [DefaultSoapUICore] Defaulting to native L&F for Mac OS X
2014-01-28 11:40:41,637 INFO  [SoapUI] Used java version: 1.7.0_51
2014-01-28 11:40:42,934 INFO  [DefaultSoapUICore] Adding actions from [/Users/marcpa/Code/soapui/marcpa00-soapui/soapui/actions/demo-actions.xml]
```