Adding ability to specify an alternative release/installation directory.
Adding ability to specify an alternative release/installation directory.

usage:  make INSTALLDIR=/path/to/installation

this will create $INSTALLDIR/dist/linux64/[lib|bin...]





git-svn-id: 93cebb81a0f5cc00f31a7ad40d16024532691b70@618 a3683778-fedd-11de-87c3-653bb6514e15

brechtvl/OpenShadingLanguage,mcanthony/OpenShadingLanguage,aconty/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,juvenal/OpenShadingLanguage,rlmh/OpenShadingLanguage,svenstaro/OpenShadingLanguage,Anteru/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,sjparker/OpenShadingLanguage,imageworks/OpenShadingLanguage,Anteru/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,brechtvl/OpenShadingLanguage,juvenal/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,gzorin/OpenShadingLanguage,brechtvl/OpenShadingLanguage,aconty/OpenShadingLanguage,svenstaro/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,gzorin/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,sjparker/OpenShadingLanguage,Anteru/OpenShadingLanguage,rlmh/OpenShadingLanguage,aconty/OpenShadingLanguage,brechtvl/OpenShadingLanguage,svenstaro/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,svenstaro/OpenShadingLanguage,Anteru/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,brechtvl/OpenShadingLanguage,mcanthony/OpenShadingLanguage,sjparker/OpenShadingLanguage,rlmh/OpenShadingLanguage,gzorin/OpenShadingLanguage,mcanthony/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,imageworks/OpenShadingLanguage,juvenal/OpenShadingLanguage,lgritz/OpenShadingLanguage,mcanthony/OpenShadingLanguage,lgritz/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,juvenal/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,gzorin/OpenShadingLanguage,aconty/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,aconty/OpenShadingLanguage,sjparker/OpenShadingLanguage,rlmh/OpenShadingLanguage,gzorin/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,lgritz/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,imageworks/OpenShadingLanguage