Eclipse OmeroJava src (rebased onto develop)



This is the same as gh-1470 but rebased onto develop.

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After @bpindelski's recent changes to tools/OmeroJava,
there is no longer any source under OmeroJava, but build-eclipse
produced a .classpath file which referenced it leaving the workspace
broken.

Re-running `./build.py build-dev` with this change should produce
a new working Eclipse classpath file.