Merge 'next' branch to 'master'

Merge 'next' branch to 'master'.

This commit 
  ca4efde [rilmodem] Fix for call waiting status query
has already been reviewed via mail.

The other 15 commits have already been reviewed in earlier pull requests:
PR#122:
  04277bc Fixed memory leak in provision_get_settings
PR#124:
  c2db8e1 [rilmodem] Enhancing traces
PR#125:
  8dee8f7 [gril]send all commands before destroying watch
  623bd22 [gril]revert grilio back to original
PR#127:
  4d1c78b [rilmodem] Do not close the ofono if rild dies
  753b316 [ofono] Handle gril ioconnection shutdown by exit
PR#130:
  1c30b64 [rilmodem] Configure the tech preference only once
PR#131:
 4cc5982 [gdbus] Handle dbus disconnect signal
PR#132:
  b4518cd [rilmodem] Call direction bookkeeping
PR#133:
  7fdb1fe [rilmodem] Remove unnecessary 'fake' held status when dialing 2nd call
PR#136:
  543fb0e [ril] fix merge and some style issues
  caa16fb [ril] Multiple PDP context support for rilmodem
  9dee219 [ril] run ofono as root
  87f4764 [ril] Leave extra capabilities as radio cannot set IP address
PR#141:
  6855781 [voicecall] Fix compiler warnings