Fixed parsing of ocamldep output for post 3.12 versions.

ocamldep version 4.01 adds an extra space to its output that causes OcaIDE to try to use a file named ":"

    diff 3.12.assert.ml-deps 4.01.assert.ml-deps 
    1,2c1,2
    < assert.cmo: assert.cmi
    < assert.cmx: assert.cmi
    ---
    > assert.cmo : assert.cmi
    > assert.cmx : assert.cmi

This results in the mysterious error message: "Path must include project and resource name: /:"

This patch fixes the problem while retaining backward compatibility by ignoring any file named ":" when parsing the ocamldep output.