Fix extPanId size in NCP scan result packet (#163)
Fix extPanId size in NCP scan result packet (#163)

* Fix extPanId size in NCP scan result packet

wpantund scan result handler expects extPanId size to be 0 or 8. If not
- it stops scan result handling. Because mExtPanId is a pointer, it's
size is architecture dependent, and scanning (by chance) works only on
64bit machines. extPanId size should be (is) a constant.

* ncp: Use extPanId size from Thread API headers

OT_EXT_PAN_ID_SIZE is defined in Thread API headers. This removes
dependecy from Thread source files.

jjlee3/openthread,srickardti/openthread,mszczodrak/openthread,vaas-krish/openthread,abtink/openthread,turon/openthread,fbsder/openthread,vaas-krish/openthread,gandreello/openthread,chshu/openthread,gandreello/openthread,pvanhorn/openthread,JakubBrachTieto/openthread,xiaom-GitHub/openthread,chshu/openthread,pvanhorn/openthread,jjlee9/openthread,jwhui/openthread,mszczodrak/openthread,fbsder/openthread,LeZhang2016/openthread,xiaom-GitHub/openthread,JakubBrachTieto/openthread,gandreello/openthread,lanyuwen/openthread,vaas-krish/openthread,erja-gp/openthread,lanyuwen/openthread,librasungirl/openthread,mszczodrak/openthread,jwhui/openthread,gandreello/openthread,Zolertia/openthread,nibanks/openthread,Zolertia/openthread,lanyuwen/openthread,gandreello/openthread,xiaom-GitHub/openthread,LeZhang2016/openthread,jjlee3/openthread,librasungirl/openthread,fbsder/openthread,aeliot/openthread,pvanhorn/openthread,openthread/openthread,chshu/openthread,georgecpr/openthread,erja-gp/openthread,abtink/openthread,GiedriusM/openthread,jjlee3/openthread,librasungirl/openthread,aeliot/openthread,nibanks/openthread,vaas-krish/openthread,GiedriusM/openthread,nibanks/openthread,jjlee9/openthread,erja-gp/openthread,aeliot/openthread,jjlee3/openthread,Zolertia/openthread,fbsder/openthread,bukepo/openthread,pvanhorn/openthread,Zolertia/openthread,chshu/openthread,fbsder/openthread,jjlee9/openthread,nibanks/openthread,JakubBrachTieto/openthread,georgecpr/openthread,GiedriusM/openthread,gandreello/openthread,abtink/openthread,openthread/openthread,aeliot/openthread,srickardti/openthread,abtink/openthread,jwhui/openthread,bukepo/openthread,georgecpr/openthread,aeliot/openthread,bukepo/openthread,Zolertia/openthread,LeZhang2016/openthread,vaas-krish/openthread,JakubBrachTieto/openthread,aeliot/openthread,lanyuwen/openthread,mszczodrak/openthread,librasungirl/openthread,jjlee9/openthread,nibanks/openthread,lanyuwen/openthread,openthread/openthread,JakubBrachTieto/openthread,LeZhang2016/openthread,pvanhorn/openthread,georgecpr/openthread,erja-gp/openthread,xiaom-GitHub/openthread,srickardti/openthread,georgecpr/openthread,jjlee3/openthread,jjlee9/openthread,turon/openthread,chshu/openthread,georgecpr/openthread,chshu/openthread,JakubBrachTieto/openthread,mszczodrak/openthread,erja-gp/openthread,openthread/openthread,lanyuwen/openthread,vaas-krish/openthread,fbsder/openthread,bukepo/openthread,erja-gp/openthread,jwhui/openthread,jjlee9/openthread,nibanks/openthread,GiedriusM/openthread,xiaom-GitHub/openthread,xiaom-GitHub/openthread,srickardti/openthread,GiedriusM/openthread,LeZhang2016/openthread,pvanhorn/openthread,turon/openthread,LeZhang2016/openthread,turon/openthread,mszczodrak/openthread