Fix grammar error on `README.md`.

Fix phrase "given data is a file (that) was uploaded" on `uploaded`
validation rule.
Domain rules now can skip TLD checks and accepts IDNA.

Skipping TLD check allows for local domains like "machine.dev",
but the default behavior of the rule still the same: it validates
TLDs, so domains will only be valid (by default) if the TLD is a
valid one.

The signature of rule (using the builder) changes from:

    v::domain() // Still works, same behavior as before.

To:

    v::domain(false) // Skips TLD check.

Fix #33.

The "Domain" rule now validates domains on "ASCII Compatible Encoding"
[ACE][1] for internationalized domain names (ICANN, 2003).

An excerpt from Wikipedia article:

> If given a label containing at least one non-ASCII character, ToASCII
> will apply the Nameprep algorithm, which converts the label to
> lowercase and performs other normalization, and will then translate the
> result to ASCII using [Punycode][16] before prepending the four-character
> string ["xn--"][17].

[1]: http://wikipedia.org/wiki/Internationalized_domain_name#ToASCII_and_ToUnicode
[16]: http://tools.ietf.org/html/rfc3492
[17]: http://www.atm.tut.fi/list-archive/ietf-announce/msg13572.html
Add TLDs "post" and "xxx".
Merge pull request #148 from augustohp/develop

Allow internationalized domains and skip TLD check.