Refactoring unit class to use boost::scoped_ptr instead of raw pointer.

This change aims to simplify the code, making the intents more explicit.
There wasn't a memory leak in the previous version, but it could easily be
introduced in the future.

Also, RAII is part of the coding standards of Wesnoth, as noted in the wiki.

There are other raw pointers in the unit class, but unit don't own them, then
I leave them unchanged.
Travis config
Travis config update
Another travis config update
Travis config: clang
Merge branch 'master' into travis
Colorize travis output
Merge branch 'master' into travis
Color changes
Build every branch that is pushed
Merge branch 'master' into travis
We don't need boost::thread anymore
Cat config.log if the build fails
Merge branch 'master' into travis
Merge branch 'master' into travis
The scons thing seems to be fixed
Disabled (hopefully) the ogg tag reading on Win and Mac.

The scons build system still asks for the library,
thus the compiling might still be broken on scons based builds.
Implemented the editor item tool.
Fix the editor theme at default resolution to match the new art set.
Fixed a merge conflict that made it in my repository.

Reverting the commit ends up in the "git revert" command not
terminating. I do not know what to do else.