Cleanup a number of things with plugins:

- Drop unneeded rpath
- Drop unneeded so version-info
- Handle test plugins by removing them after install

plugins/Makefile.am

@@ -5,7 +5,7 @@
 include $(top_srcdir)/lib_flags.am
 
 AM_LDFLAGS += -module -avoid-version -shared -export-dynamic	\
- -rpath ${abs_builddir} ${NOUNDEFINED}
+ ${NOUNDEFINED}
 
 # Create an alternate directory if not installing or for noinst installs.
 ALTPLUGINDIR = ${abs_top_builddir}/plugins/plugindir
@@ -19,17 +19,6 @@ endif
 
 plugin_LTLIBRARIES =
 
-# Apparently one cannot have plugin_LTLIBRARIES and also noinst_LTLIBRARIES.
-# So create a tmp location for "noinst" shared libraries.
-tmpdir = ${ALTPLUGINDIR}
-
-tmp_LTLIBRARIES =
-
-# This linker flag specifies libtool version info.
-# See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning
-# for information regarding incrementing `-version-info`.
-plugin_version_info = -version-info 0:0:0
-
 if ISMINGW
 LDADD =  ${top_builddir}/liblib/libnetcdf.la
 endif
@@ -55,15 +44,10 @@ lib__nch5shuffle_la_SOURCES = H5Zshuffle.c
 lib__nch5fletcher32_la_SOURCES = H5Zfletcher32.c H5checksum.c
 lib__nch5deflate_la_SOURCES = H5Zdeflate.c
 
-lib__nch5shuffle_la_LDFLAGS = ${plugin_version_info}
-lib__nch5deflate_la_LDFLAGS = ${plugin_version_info}
-lib__nch5fletcher32_la_LDFLAGS = ${plugin_version_info}
-
 # Need our version of szip if libsz available and we are not using HDF5
 if HAVE_SZ
 plugin_LTLIBRARIES += lib__nch5szip.la
 lib__nch5szip_la_SOURCES = H5Zszip.c H5Zszip.h
-lib__nch5szip_la_LDFLAGS = ${plugin_version_info}
 endif
 
 endif # ENABLE_NCZARR_FILTERS
@@ -79,13 +63,11 @@ plugin_LTLIBRARIES += lib__nczstdfilters.la
 
 if HAVE_BLOSC
 lib__nch5blosc_la_SOURCES = H5Zblosc.c H5Zblosc.h
-lib__nch5blosc_la_LDFLAGS = ${plugin_version_info}
 plugin_LTLIBRARIES += lib__nch5blosc.la
 endif
 
 if HAVE_ZSTD
 lib__nch5zstd_la_SOURCES = H5Zzstd.c H5Zzstd.h
-lib__nch5zstd_la_LDFLAGS = ${plugin_version_info}
 plugin_LTLIBRARIES += lib__nch5zstd.la
 endif
 
@@ -95,20 +77,19 @@ endif #ENABLE_PLUGINS
 # Need two distinct instances
 lib__nch5noop_la_SOURCES = H5Znoop.c H5Zutil.c h5noop.h
 lib__nch5noop1_la_SOURCES = H5Znoop1.c H5Zutil.c h5noop.h
-lib__nch5noop_la_LDFLAGS = ${plugin_version_info}
-lib__nch5noop1_la_LDFLAGS = ${plugin_version_info}
 
 # The misc filter is to allow testing of filter arguments
 lib__nch5misc_la_SOURCES = H5Zmisc.c H5Zutil.c h5misc.h
-lib__nch5misc_la_LDFLAGS = ${plugin_version_info}
 lib__nczmisc_la_SOURCES = NCZmisc.c
-lib__nczmisc_la_LDFLAGS = ${plugin_version_info}
 
 # Provide a filter to test missing filter
 lib__nch5unknown_la_SOURCES = H5Zunknown.c
-lib__nch5unknown_la_LDFLAGS = ${plugin_version_info}
 
-tmp_LTLIBRARIES += lib__nch5noop.la lib__nch5noop1.la lib__nch5misc.la lib__nczmisc.la lib__nch5unknown.la
+CHECKLIBS = lib__nch5noop.la lib__nch5noop1.la lib__nch5misc.la lib__nczmisc.la lib__nch5unknown.la
+plugin_LTLIBRARIES += ${CHECKLIBS}
+
+install-data-hook:
+	cd $(DESTDIR)$(plugindir) && rm -f $(CHECKLIBS) $(CHECKLIBS:.la=.so)
 
 # Bzip2 is used to test more complex filters
 lib__nch5bzip2_la_SOURCES = H5Zbzip2.c h5bzip2.h
@@ -117,7 +98,6 @@ EXTRA_DIST += ${BZIP2SRC} BZIP2_LICENSE
 if HAVE_LOCAL_BZ2
 lib__nch5bzip2_la_SOURCES += ${BZIP2SRC}
 endif
-lib__nch5bzip2_la_LDFLAGS = ${plugin_version_info}
 plugin_LTLIBRARIES += lib__nch5bzip2.la
 
 endif #ENABLE_FILTER_TESTING