Parse FCL_LDFLAGS

[cielavenir]

Since we already have used the technique in bulletrave, why don't we use it also in fclrave? And I updated bulletrave comment as well.

As current origin/master and origin/production are the same, it is up to you which to merge.

Note: if this is merged, please close #640

[rdiankov]

does "${PLUGIN_LINK_FLAGS}" ${FCL_LDFLAGS}work?

[cielavenir]

@rdiankov I confirmed that would cause #633 if /usr/local/lib/pkgconfig/fcl.pc's Libs is only -lfcl. Usual fcl.pc.in has Libs -L${libdir} -lfcl, so we were not aware the corner case.

[cielavenir]

#795 appeared...

[cielavenir]

closing this one