Merge 3.1.0 development branch into trunk

Branch in question is 'env' branch from git://git.springsource.org/sandbox/cbeams.git; merged into
git-svn repository with:

    git merge -s recursive -Xtheirs --no-commit env

No merge conflicts, but did need to

    git rm spring-build

prior to committing.

With this change, Spring 3.1.0 development is now happening on SVN
trunk. Further commits to the 3.0.x line will happen in an as-yet
uncreated SVN branch.  3.1.0 snapshots will be available
per the usual nightly CI build from trunk.

build.properties

@@ -1,4 +1,4 @@
-version=3.0.5
+version=3.1.0
 # osgi ranges
 spring.osgi.range.nq=${version:[=.=.=, =.=.+1)}
 spring.osgi.range="${spring.osgi.range.nq}"