package.bbclass: Rewrite shlib_provider handling to include RPATH

package.bbclass: Rewrite shlib_provider handling to include RPATH

Change the do_package shlibs code to account for RPATHS. This means that
for library dependency purposes, only libraries in system paths or in
any declared RPATH will be seen. This is important to resolve problems
people have been having where similarly named libraries in "private"
paths were conflicting, e.g. with gstreamer.

For now this code assumes the default search path is libdir and
base_libdir and places ASSUME_SHLIBS in libdir so they are searched by
default.

(From OE-Core rev: 48b9ecd5335f63fb2bcc47c4b23d067122734fe9)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>