Squashed commit of ca128f7dcd28cbcfba154c8577ed54d4aa71dd02 with
contributions from Mark Constable (markc@renta.net) and Daniel Gröber
(darklord@darkboxed.org).

Broke require('constants'). Add unrelated test which breaks it.

doesn't contain addresses, causing ares_parse_a_reply() to bail out with
ARES_ENODATA.

fixes test/simple/test-fs-sir-writes-alot.js on mac

with tests

Fix module path resolve bug.  Normally the module path is taken from
realpath(__filename) but with eval there is (of course) no filename

(now that requireNative does not depend on path module)

This reverts commit cd9515ef, reversing
changes made to df46c8e6.

Too slow. Needs more work.

This reverts commit 464ced4a.

This reverts commit a9363400.