Remove the major.minor version from the plugin path, i.e:
lib/plugins/X.Y/{epan,wiretap,codecs}
and use an unversioned path:
lib/plugins/{epan,wiretap,codecs}
Introduce a new naming policy for plugins that requires
name.so.ABI_VERSION.
This is a simplified filesystem layoutfor plugins some
important benefits such as:
* improves compatibility between Wireshark versions, because
a plugin that wasn't recompiled will be automatically picked
up, but only if it has a compatible ABI version in the file name.
* does not clash with Apple guidelines
* simpler for users to understand and apply
* just overall simpler and easier to maintain, removes a lot
of complexity from CMake code
It does impose more requirements on the plugin naming scheme
but this should be handled completely transparently
by the build system.
It would also be possible to add support for unversioned *.so file
extensions at the same time, although in ths case it is not possible
to support multiple Wireshark ABI versions with only *.so, of course.
This wasn't done here but it may or may not be a useful enhancement
in the future.
Follow-up to 90b16b4092.
Move the libwireshark pkgconfig file to the resource directory.
Set the various paths in our .pc files based on the `pcfiledir` variable
instead of using absolute paths. This should make it possible to install
using a DESTDIR that differs from CMAKE_INSTALL_PREFIX.
João Valverde