Get rid of rapidxml

[Google Code Exporter]

In order to reduce trex core dependencies we are in the process to get rid of 
rapidxml and replace it by Boost.PropertyTree (which is actually using rapidxml 
under the hood for now but they also plan to rely on a more standard parser in 
the future)

The correction are underway already and will be committed soon. They proved so 
far that while they potentially do impact  third party extensions (we have to 
replace all the references to rapidxml to the boost::property_tree equivalent), 
this impact remains minimum. 

Still we need to make sure that :
  - the integration will go smoothly for users (and 3rd party developer) 
  - references in the documentation and other places to rapidxml are removed 
  - things are still behaving as they used to after the update

Original issue reported on code.google.com by [e-mail] on 27 Oct 2011 at 4:10

[Google Code Exporter]

It appears that the change from rapidxml toward boot.property tree worked fine 
and since r121 both the INSTALL file and general documentations have been 
updated accordingly.

A mail have been also posted on the mailing list  to indicate that the version 
0.3.0 and above will now use boost property tree and above

Original comment by [e-mail] on 7 Dec 2011 at 6:08

• Changed state: Fixed

[Google Code Exporter]

Read r211 above for the revision where the updates where done

Original comment by [e-mail] on 7 Dec 2011 at 6:11