Minor adjustments to jax Makefiles and added a test target to top makefile

[Kelly O'Hair]

Changes on their way...  doing full builds to try them out.

6960333: Add make level ALLOW_DOWNLOADS=true option
6960335: Add top level 'make test' rule that uses test/Makefile, runs  
all test batches

http://cr.openjdk.java.net/~ohair/openjdk6/jax-make-test-allow/webrev/

Minor jaxp/jaxws makefile adjustment, and a new top level Makefile  
"test" target.

Next time you build the entire openjdk6 forest, try doing it with:
    make && make test

Or if you have a N (N>1) cpu machine, try:
   make && make -j N test      e.g. make && make -j 4 test

If tests fail, let me know. The -j option runs the test batches in  
parallel
and they can sometimes cause strange failures if tests use the same  
port.
Not using -j is more predictable but might take 2 hours.

My last -j 4 results took 15mins on Solaris 20 x86, and the failures I  
saw were:

ERROR: Test failure count:       14
FAILED: java/beans/XMLEncoder/java_u
FAILED: javax/management/MBeanServer/NewMBeanListenerTest.java
FAILED: com/sun/crypto/provider/Cipher/RSA/TestOAEP.java
FAILED: java/net/ResponseCache/getResponseCode.java               <-  
will be fixed soon
FAILED: sun/net/www/protocol/http/RelativeRedirect.java           <-  
will be fixed soon
FAILED: sun/net/www/protocol/http/StackTraceTest.java             <-  
will be fixed soon
FAILED: sun/tools/jconsole/ImmutableResourceTest.sh
FAILED: tools/pack200/Pack200Simple.sh
FAILED: sun/security/pkcs11/ec/ReadCertificates.java
FAILED: sun/security/pkcs11/ec/ReadPKCS12.java
FAILED: sun/security/pkcs11/ec/TestCurves.java
FAILED: sun/security/pkcs11/ec/TestECDSA.java
FAILED: sun/security/pkcs11/ec/TestECGenSpec.java
FAILED: sun/security/pkcs11/ec/TestKeyFactory.java

I will investigate the rest, but without -j 4 I only saw the 3 known / 
net/ failures.

Eventually these changes will make it into jdk7.

-kto