remove algorithms that where only used by dstar's dra2ba conversion

Since we just removed that conversion, those can go as well.  Yay!

* src/tests/kv.test, src/twa/twamask.cc,
src/twa/twamask.hh, src/twa/twaproxy.cc,
src/twa/twaproxy.hh, src/twaalgos/scc.cc,
src/twaalgos/scc.hh: Delete.
* src/twaalgos/Makefile.am, src/twa/Makefile.am,
src/tests/Makefile.am, src/tests/ikwiad.cc: adjust.

src/twaalgos/Makefile.am

@@ -70,7 +70,6 @@ twaalgos_HEADERS = \
   safety.hh \
   sbacc.hh \
   sccfilter.hh \
-  scc.hh \
   sccinfo.hh \
   se05.hh \
   sepsets.hh \
@@ -127,7 +126,6 @@ libtwaalgos_la_SOURCES = \
   relabel.cc \
   safety.cc \
   sbacc.cc \
-  scc.cc \
   sccinfo.cc \
   sccfilter.cc \
   se05.cc \