Fix to build for jaxp and jaxws build breaks

[Pete Brunet]

In case someone finds this useful...  This week I fcloned a new OpenJDK
for JDK7 and the build failed.  To fix this I had to do the following:

1) cd to jaxp/make and jaxws/make. Run 'make ALLOW_DOWNLOADS=true
source'  // Thanks to kto for this info.
2) copy zips in C:\OpenJDK\jdk7\jaxp\drop\bundles and
C:\OpenJDK\jdk7\jaxws\drop\bundles to C:/SlashJava/devtools/share/jdk7-drops
3) add the following environment variable to my startup bat file:
set ALT_DROPS_DIR=C:/SlashJava/devtools/share/jdk7-drops

I assume instead of using C:/SlashJava/devtools/share/jdk7-drops you can
use any other directory.

Pete