Co-authored-by: Christoph Tavan <dev@tavan.de>

Add the following new APIs:
- uuid.NIL The nil UUID string (all zeros)
- uuid.parse() Convert UUID string to array of bytes
- uuid.stringify() Convert array of bytes to UUID string
- uuid.validate() Test a string to see if it is a valid UUID
- uuid.version() Detect RFC version of a UUID

This commit also adds more accurate validation when stringifying UUIDs and improves UUID parsing performance (for v3/v5 UUIDs) significantly (Thanks @awwit!).

Co-authored-by: Christoph Tavan <dev@tavan.de>
Co-authored-by: Ignat Prokopovich <ignatius.awwit@gmail.com>
Co-authored-by: Robert Kieffer <robert@broofa.com>
Co-authored-by: Linus Unnebäck <linus@folkdatorn.se>

Closes #485

With the added tests IE11 tests have become flaky since they simply seem
too sloooooooooooow. The tests in IE11 take up to 1:30 to run while they
usually finish after around 30s in all other browsers.

Wdio executes tests in order. We have 5 concurrent execution slots at
BrowserStack. Since the IE tests take by far the longest time (1:30
instead of 0:30 for all others) it makes sense to run them first. Safari
tests seem to execute the fastes, so run them last.

The new APIs are introduced in 8.3, not 8.2.

The new APIs were still missing from some environment-specific tests. We
should definitely consider consolidating these environment-specific test
cases somehow, this currently requires way too much manual work and it's
too easy to miss certain places that need an update.