- Add libproxy-force-bipr.patch: Force building pacrunner as module
This is required as libproxy, when building only one pacrunner,
links the module internal. But as we only temporarly disable
the mozjs, we do need to keep the webkit runner as an external
module.
- Also pass -DBIPR=0 to cmake, to enable the patch above.

- Temporaryly disable the mozjs pacrunner: it casues crashes due
to symbol conflicts in Firefox (bnc#759123):
+ Introduce build_mozjs defnies, currently set to 0
+ Conditionally build the pacrunner-mozjs package
+ conditionally buildrequire pkgconfig(mozjs185)
+ When not building mozjs pacrunner, obsolete the package by
libproxy1.

- Add libproxy-force-bipr.patch: Force building pacrunner as module
This is required as libproxy, when building only one pacrunner,
links the module internal. But as we only temporarly disable
the mozjs, we do need to keep the webkit runner as an external
module.
- Also pass -DBIPR=0 to cmake, to enable the patch above.

- Temporaryly disable the mozjs pacrunner: it casues crashes due
to symbol conflicts in Firefox (bnc#759123):
+ Introduce build_mozjs defnies, currently set to 0
+ Conditionally build the pacrunner-mozjs package
+ conditionally buildrequire pkgconfig(mozjs185)
+ When not building mozjs pacrunner, obsolete the package by
libproxy1. (forwarded request 124317 from dimstar)