PR#92 update: use $ORIGIN/../lib for custom installed boost libraries

[venediktov]

No description provided.

[venediktov]

@innerNULL these changes are needed for:

• to support both Linux and Mac please see cmake file(DOWNLOAD...) instead of wget
• $ORIGIN/../lib is needed for boost libraries as well, because those are not deployed to /usr/loca/bin , therefore because vanilla-rtb uses rpath instead of LD_LIBRARY_PATH we need to inject it into boost DLLs
• prevent re-download boost sources -> boost.tar.gz
• Boost 1.67.0 EXACT is needed for -DGET_BOOST so that cmake does not pull higher version of boost from official install when we use custom build/location

If those changes merged to your dev branch they will appear in your PR [venediktov#92] , you can also add your suggestions.