package.bbclass: Improve shlibs pkgdata file format

package.bbclass: Improve shlibs pkgdata file format

Instead of having a .list file and a .ver file, place the version
information into the .list file in a ":" delimited string.

Also place the path to the library here, this can then be used to
evaluate RPATHs in the shlib dependency code.

Since the disk format has changed, the easiest way to avoid build
failures in the same TMPDIR is to change the shlibs directory to
shlibs2. sstate dependency code with ensure everything rebuilds.

(From OE-Core rev: 8dd09b3ddc572a338b4a6f1d859b68b2b4482d00)

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