BZ #179: configure does not check if jasmin is usable

Status fields:

The configure script does not check if jasmin exists and/or is usable. This causes `make
check` to fail with:

<output>
Making check in bugzilla
make[3]: Entering directory `/home/zapster/cacao/cacao-build/tests/regression/bugzilla'
LD_LIBRARY_PATH=../../../src/cacao/.libs ../../../src/cacao/cacao
-Xbootclasspath:../../../src/classes/classes:/home/zapster/cacao/cacao-build
/../classpath-install/share/classpath/glibj.zip -cp
/usr/share/java/cup.jar:/usr/share/java/jasmin-sable.jar jasmin.Main ../../..
/../cacao-staging/tests/regression/bugzilla/*.j
Exception in thread "main" java.lang.NoClassDefFoundError: jasmin.Main not found in
java.lang.ClassLoader$1{urls=[file:/usr/share/java/cup.jar,file:/usr/share/java/jasmin-
sable.jar], parent=null}
   <<No stacktrace available>>
Caused by: java.lang.ClassNotFoundException: jasmin.Main not found in
java.lang.ClassLoader$1{urls=[file:/usr/share/java/cup.jar,file:/usr/share/java/jasmin-
sable.jar], parent=null}
   at java.net.URLClassLoader.findClass(URLClassLoader.java:531)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:341)
   at java.lang.ClassLoader$1.loadClass(ClassLoader.java:1112)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:293)
make[3]: *** [build] Error 1
make[3]: Leaving directory `/home/zapster/cacao/cacao-build/tests/regression/bugzilla'
make[2]: *** [check-recursive] Error 1
make[2]: Leaving directory `/home/zapster/cacao/cacao-build/tests/regression'
make[1]: *** [check-recursive] Error 1
make[1]: Leaving directory `/home/zapster/cacao/cacao-build/tests'
make: *** [check-recursive] Error 1
</output>


This might be confusing to some users. configure should emit a warning.