Serialization was a cool idea for handling the temp load/unload problem,
however the usecase these days does not often involve that in order
to justify its continued maintainence.

"http://www.compiz-fusion.org" is not existent anymore and leads one to the "Web Design Manchester" web design business page (used in the About dialogue of CCSM for example) and
"http://www.compiz.org" is outdated and does not reflect actual development of Compiz anymore

required to find FindOpenGLES2.cmake when building Unity with
-DBUILD_GLES=ON
(LP: #1039448)

(LP:#1030176)

unless the user explicitly changed the CMAKE_INSTALL_PATH.

Rationale: If the user has their PKG_CONFIG_PATH set to /foo/bar
they would expect that when doing things like, eg installing plugins
locally (which ignores CMAKE_INSTALL_PREFIX), that the buildsystem
would pick up pkg-config files from their PKG_CONFIG_PATH which they
have specified themselves and not the default CMAKE_INSTALL_PREFIX,
however when the user changes the CMAKE_INSTALL_PREFIX they need
to have that be used for pkg-config purposes.