I have disabled the test-string-decoder.js test, as this test now fails
with the latest version of nodejs (4.1.2) in Debian unstable.

Currently, node-string-decoder provides the version of string-decoder
from v0.10.25 of node-core. So this failing test should not matter for
reverse dependencies expecting this version of string-decoder.

I have asked upstream (rvagg) when support of the new LTS nodejs (v4.1.2)
will be provided in node-string-decoder, and raised an issue at:
https://github.com/substack/string_decoder/issues/4
