Make sed usage more compatible

... and a bit less safe

Might close #35

Makefile

@@ -50,7 +50,7 @@ include $(PGXS)
 $(EXTENSION)--$(EXTVERSION).sql: $(CDBSCRIPTS) cartodb_version.sql Makefile 
 	echo '\echo Use "CREATE EXTENSION $(EXTENSION)" to load this file. \quit' > $@
 	cat $(CDBSCRIPTS) | \
-    $(SED) -e 's/\<public\./cartodb./g' \
+    $(SED) -e 's/public\./cartodb./g' \
         -e 's/:DATABASE_USERNAME/cdb_org_admin/g' >> $@
 	echo "GRANT USAGE ON SCHEMA cartodb TO public;" >> $@
 	cat cartodb_version.sql >> $@
@@ -82,7 +82,7 @@ legacy_regress: $(REGRESS_OLD) Makefile
     echo '\\t' >> $${of}; \
     echo '\\set QUIET off' >> $${of}; \
     cat $${f} | \
-      $(SED) -e 's/\<public\./cartodb./g' >> $${of}; \
+      $(SED) -e 's/public\./cartodb./g' >> $${of}; \
     exp=expected/test/$${tn}.out; \
     echo '\\set ECHO off' > $${exp}; \
     cat test/$${tn}_expect >> $${exp}; \