Restore tabs: Disable updates of tabbar while restoring session.

Fixes sometimes drawing tabbar while restoring is in process, resulting
in painting only few tabs and then all restored tabs after a moment.
It will now only draw completely restored tabbar.

Also fixed one incorrect usage of setUpdatesEnabled in TreeWidget.
Translations: Generate empty.ts with lines from source code.
Coding style + changed line endings of copyright
Added new Catalan translation.

Thanks to Guillem Prats and Clara Villalba.
Fixed copying url with special characters into clipboard.

Also properly encode url for loading in W3 validator.

Followup to #762
GreaseMonkey: Don't load invalid scripts.
NetworkManager: Use certificates from bundle only on Windows.

On other platforms, let's just use system certificates.
[Qt5] Use RegExp wrapper to take advantage of new regexp engine.

QzRegExp wrapper is using QRegExp directly on Qt 4 and
QRegularExpression (with PCRE engine) on Qt 5.
GreaseMonkey: Bumped plugin version.
Updated certificate bundle + build it only on Windows.
Merge pull request #780 from srazi/master

[Windows] Don't update transparent margins on close.
[Mac] Fixes font rendering with HiDPI (retina) displays.
Preferences: Fixed showing current language in languages menu.
[Mac] Little modifications in theme for better native look.

Closes #765
Show Mac OS X version in QzTool::operatingSystem.

It now also supports Windows 8 detection.

Function have been renamed from buildSystem to operatingSystem
as it does not really returns build system anymore.
[Qt5] Fixed getting correctly QtWebKit version with pkg-config.

QtWebKit module is named Qt5WebKitWidgets in Qt 5.
Versioning is also different from Qt 4.
[PageFormCompleter] Don't try to extract form if formdata is invalid.
[AutoFill] Show key icon only when password was actually filled in page.

If you have saved multiple passwords eg. for gmail.com, it will now
only show key icon when trying to login, instead of showing it all the
time on gmail.com (even after logging in).
Properly destroy NetworkManager on application close.
Significant memory savings in AdBlock (~ 30MB with just EasyList)

Even empty QRegExp can occupy a lot of space in memory, which can
grow into a big number with tens of thousands AdBlock rules.
QRegExp is now allocated with new, and only when really needed.