modules/ims_charging: new module for IMS charging
	- currently supports Ro interface
add IMS-Charging to Makefile.groups
Initial structure for the docs of the IMS-Charging module (incomplete)
Bug-Fixes:
- Use P-Asserted-Identity instead of From-Header as User in CCR
- Store RURI in the ro_session structure (it may have been changed by an Application-Server)

Fixed by: Carlos Ruiz Díaz (carlos@ng-voice.com)
Another Fix for the ims_charging Module:
- Use P-Asserted-Identity instead of From-Header

fixed by Carlos Ruiz Díaz (carlos@ng-voice.com)
avops: avp_check() xavp as first parameter
avpops: update avp_check documentation related to xavp vars as parameters
avpops: refresh README
core: updated parse_param so that the delimiter for parameters can be user-defined
pv: updated param transformations so that you can (optionally) specify what the parameter delimiter is

- default behaviour unchanged
- this allows HTTP URL parameters to be decoded
xhttp: added transformation to break a URL into "path" and "querystring"
mi_rpc: compatibility with libxmlrpc-c3 library on wheezy

- patch by Muhammad Shahzad
presence_xml: updated docs about integrated_xcap_server
db_mysql: unlock tables at the end of transaction if they were locked
Move assert_identity to ims_usrloc_pcscf as we may have more than one IMPI per Port/IP/Proto
pv: tweaked {param.} transformation so that if the (optional) delimiter parameter is changed between runs the param string is reparsed
xhttp: cache the URL string when performing transformations so sequential transformations on the same string do not require a reparse.
pkg/kamailio/centos: updated .spec for CentOS 6

- Added gzcompress
- Updated rel to dev9
ims_charging: added async support

- Ro_ccr is now called asynchronously and resumed on an external custom cfg route
- Interim and final CCR are now also async
pkg/kamailio/centos: updates to CentOS 6 build

- Improved startup scripts
- Updated .spec
- README listing and explaining which Kamailio modules are not built for
  CentOS