Shared library provides/requires rpath improvements

[bdrewery]

For provides we should record the path the library was stored in.

For required we should record the RPATH the binaries are looking in.

For the solver we should not only consider SONAME, but the RPATH and default LD_LIBRARY_PATHs for making a match.

[davidchisnall]

It would be good to have Poudriere in test-port mode check for anything that looks like a shell script and includes LD_LIBRARY_PATH as well. Those will need some annotation telling pkg where to look for provided libraries.

[theLOICofFRANCE]

up, please.