MNT: rename cluster to fsl-cluster to avoid naming conflicts with third party packages.

We have known for a long time that $FSLDIR/bin/cluster collides with the graphviz cluster command. With the move to using conda for distribution/installation, we will now potentially be sharing the $FSLDIR/bin/ namespace with graphviz. So cluster is being renamed to fsl-cluster.

A wrapper script called $FSLDIR/share/fsl/bin/cluster will be maintained for compatibility with older releases, so that end users and third party scripts can still call cluster.

Makefile

@@ -4,7 +4,7 @@ PROJNAME = cluster
 
 LIBS = -lfsl-warpfns -lfsl-meshclass -lfsl-basisfield -lfsl-newimage -lfsl-miscmaths -lfsl-NewNifti  -lfsl-cprob -lfsl-utils -lfsl-znz
 
-XFILES = smoothest cluster connectedcomp
+XFILES = smoothest fsl-cluster connectedcomp
 
 SCRIPTS = cluster2html
 
@@ -16,7 +16,10 @@ smoothest: smoothest.o
 infertest: infertest.o infer.o
 	${CXX} ${CXXFLAGS} -o $@ $^ ${LDFLAGS}
 
-cluster: cluster.o infer.o
+# We name the binary "fsl-cluster"
+# to avoid collision with the
+# graphviz "cluster" command.
+fsl-cluster: cluster.o infer.o
 	${CXX} ${CXXFLAGS} -o $@ $^ ${LDFLAGS}
 
 connectedcomp: connectedcomp.o