gyp: fix post-mortem in v0.11

Expose missing constants and keep symbols on OSX.
doc: console.trace takes a message format

Documentation claimed it accepted a single label argument, as time and
timeEnd do, which was incorrect.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
test: fix  test-tls-server-verify

fix #7963
test: fix test-https-foafssl
buffer: fix sign overflow in `readUIn32BE`

`|` operation takes precendence on `+`, which will result in
`new Buffer('ffffffff', 16).readUInt32BE(0)` returning `-1` instead of
`ffffffff`.
timers: backport f8193ab.

Original commit message:

 timers: use uv_now instead of Date.now

 This saves a few calls to gettimeofday which can be expensive, and
 potentially subject to clock drift. Instead use the loop time which
 uses hrtime internally.

In addition to the backport, this commit:
 - keeps _idleStart timers' property which is still set to
   Date.now() to avoid breaking existing code that uses it, even if
   its use is discouraged.
 - adds automated tests. These tests use a specific branch of
   libfaketime that hasn't been submitted upstream yet. libfaketime
   is git cloned if needed when running automated tests.