Add note about PHP's include_path.
Add note about PHP's include_path.

Refs #2497

garethellis36/cakephp,bravo-kernel/cakephp,HavokInspiration/cakephp,ADmad/cakephp,davidyell/cakephp,jerems02/cakephp,eboominathan/cakephp,web-player/cakephp,kumamidori/cakephp,dakota/cakephp,Phillaf/cakephp,dkarvounaris/cakephp,tisu2tisu/cakephp,khoimt/cakephp-study,burriko/cakephp,davidyell/cakephp,CakeDC/cakephp,tisu2tisu/cakephp,thinkingmedia/cakephp,elboletaire/cakephp,dakota/cakephp,justinyost/cakephp,timhoeppner/cakephp,justinyost/cakephp,tgr0ss/cakephp,khoimt/cakephp-study,kumamidori/cakephp,eboominathan/cakephp,tenkoma/cakephp,et304383/passbolt_api,et304383/passbolt_api,mvdriel/cakephp,akintoey/cakephp,ionas/cakephp,Phillaf/cakephp,adopico/cakephp,cakephp/cakephp,ADmad/cakephp,timhoeppner/cakephp,Balachan27/cakephp,eryw/cakephp,burriko/cakephp,mvdriel/cakephp,michaelze/cakephp,dkarvounaris/cakephp,jjj117/cakephp,jjj117/cakephp,bravo-kernel/cakephp,eryw/cakephp,adopico/cakephp,yinhe007/cakephp,kumamidori/cakephp,eboominathan/cakephp,michaelze/cakephp,cakephp-fr/cakephp,petteyg/cakephp,petteyg/cakephp,ionas/cakephp,ndm2/cakephp,CakeDC/cakephp,CVO-Technologies/cakephp,web-player/cakephp,michaelze/cakephp,dakota/cakephp,Phillaf/cakephp,et304383/passbolt_api,nrother/cakephp,timhoeppner/cakephp,eryw/cakephp,pbaire/cakephp,elboletaire/cakephp,cakephp/cakephp,mvdriel/cakephp,adopico/cakephp,yinhe007/cakephp,akintoey/cakephp,gmponos/cakephp,cakephp-fr/cakephp,nrother/cakephp,tenkoma/cakephp,tgr0ss/cakephp,dakota/cakephp,garethellis36/cakephp,ionas/cakephp,jjj117/cakephp,cakephp/cakephp,ndm2/cakephp,jerems02/cakephp,HavokInspiration/cakephp,thinkingmedia/cakephp,erikfig/cakephp,jeffblack360/cakephp,et304383/passbolt_api,berrygoudswaard/cakephp,jeffblack360/cakephp,bravo-kernel/cakephp,berrygoudswaard/cakephp,Balachan27/cakephp,ADmad/cakephp,HavokInspiration/cakephp,pbaire/cakephp,berrygoudswaard/cakephp,erikfig/cakephp,davidyell/cakephp,thinkingmedia/cakephp,mvdriel/cakephp,garethellis36/cakephp,justinyost/cakephp,gmponos/cakephp,erikfig/cakephp,web-player/cakephp,petteyg/cakephp,cakephp-fr/cakephp,cakephp/cakephp,Balachan27/cakephp,pbaire/cakephp,ndm2/cakephp,ADmad/cakephp,tgr0ss/cakephp,gmponos/cakephp,tenkoma/cakephp,petteyg/cakephp,khoimt/cakephp-study,elboletaire/cakephp,CVO-Technologies/cakephp,burriko/cakephp,jeffblack360/cakephp,dkarvounaris/cakephp,akintoey/cakephp,et304383/passbolt_api,nrother/cakephp,yinhe007/cakephp,CakeDC/cakephp,tenkoma/cakephp,jerems02/cakephp,CakeDC/cakephp,ndm2/cakephp,tisu2tisu/cakephp,garethellis36/cakephp,CVO-Technologies/cakephp