CPP: Make r570 compile in Chromium.

CPP: Make r570 compile in Chromium.

This CL ensures that:
- All declarations in headers are made in the i18n::phonenumbers namespace.
- All USE flags/macros are prefixed with I18N_PHONENUMBERS_ to avoid name
  clashes.
- All the code in base/ is actually used (by deleting unused code).
- Outdated occurrences of USE_GOOGLE_BASE don't exist anymore.
- Logging in PhoneNumberUtil is disabled by default (in production). However it
  can be enabled by calling PhoneNumberUtil::SetLogger() as it is now done
  during testing.

BUG=http://crbug.com/236272
R=jia.shao.peng@gmail.com

Committed: https://code.google.com/p/libphonenumber/source/detail?r=571

[Shaopeng, 2013-05-03 13:36:23]

On 2013/05/03 12:22:52, pliard1 wrote:

Looks like you also need to update the README file regarding the change of flag
names.

[pliard1, 2013-05-03 13:39:24]

On 2013/05/03 13:36:23, Shaopeng wrote:
> On 2013/05/03 12:22:52, pliard1 wrote:
> 
> Looks like you also need to update the README file regarding the change of
flag
> names.

Thanks Shaopeng. Note that I changed the internal flags that are passed to the
compiler rather than the CMake options' name so the information in the README is
still accurate.

[Shaopeng, 2013-05-03 13:46:47]

LGTM.

On 2013/05/03 13:39:24, pliard1 wrote:
> On 2013/05/03 13:36:23, Shaopeng wrote:
> > On 2013/05/03 12:22:52, pliard1 wrote:
> > 
> > Looks like you also need to update the README file regarding the change of
> flag
> > names.
> 
> Thanks Shaopeng. Note that I changed the internal flags that are passed to the
> compiler rather than the CMake options' name so the information in the README
is
> still accurate.

Right. Thanks for explaining.

[pliard1, 2013-05-03 13:47:30]

On 2013/05/03 13:46:47, Shaopeng wrote:
> LGTM.
> 
> On 2013/05/03 13:39:24, pliard1 wrote:
> > On 2013/05/03 13:36:23, Shaopeng wrote:
> > > On 2013/05/03 12:22:52, pliard1 wrote:
> > > 
> > > Looks like you also need to update the README file regarding the change of
> > flag
> > > names.
> > 
> > Thanks Shaopeng. Note that I changed the internal flags that are passed to
the
> > compiler rather than the CMake options' name so the information in the
README
> is
> > still accurate.
> 
> Right. Thanks for explaining.

Thanks Shaopeng!

[pliard1, 2013-05-03 13:49:46]

Committed patchset #1 manually as r571 (presubmit successful).