Overlay: Less obtrusive logging.

* Present, AddRef and Release calls are not useful most of the time.
They were only logged in DEBUG builds, but as these methods are called very often heavily degrades performance.
Add define-guards so when one actually wants to debug and see them he can enable them.
Now, (normal) debug builds will not have the heavy performance loss any more.
UserList improvements
Userlist improv.: Fix indent. Use iterator again.

* Plus a string fix.
Translation improvements
Unified channel traduction to "salon"
Merge pull request #163 from bendem/master

French translation improvments

* Updated french translation
** New translations
** Improvements to existing translations
Filtered Userlist: Refactoring. C

* Move logic into methods (in UserEdit)
* Minor formatting
* Fix memory leak (delete ueli if not passed to QTreeWidget
* Show filters and stuff when lastchantreestring is not empty, as that should always have something
(It even has something when no data comes from server though.)
fix indent
Improved Userlist: Refacs.

* Use boost::optional for explicit no data
* Move logic into method
mapping logic into protoUserToUserInfo
Userlist Improvements: Use RPC callbacks as well.

* Make getRegisteredUsersEx use RPC callbacks
* Implement UserInfo constructors
Userlist improvement: Use plural form translation
Userlist Improvements: Display localized time. Refactoring.

* The last seen datetime is now displayed in the local(ized) timezone.
* Code refactoring.
Userlist improvements: Use QDateTime.

* Use QDateTime wherever possible.
* Code refactoring
Merge branch 'pr-userlist'

Integrate feature branch for filtered and improved registration list.
This merges pull request #148.
Accountlist: Fix filtering. Windowtitle and refacs.

* Fix: Filtering by inactive days plus by name/chan is now additive.
* Adjust window title
* Code refactoring
Translation: French: Fix

* Correct "register" translation so it don't mean "register self" anymore
mumble, murmur: Qt 5 support for Linux.
mumble, murmur: Qt 5 support for Windows.
mumble: fix HWND handling for Qt 5.
mumble: fix Linux build for Qt 4 and Qt 5.