Activate -Wextra and -pedantic in debug builds.
Merge branch 'cpp11' into pedantic
Remove unused parameters.
Merge branch 'cpp11' into pedantic
Comment out unused parameters.
Remove ignored parameter.

Conflicts:

	src/entities/Hero.cpp
Disable warnings of third-party headers.
Fix wrong index in error message.
Fix unused parameters.
Remove unused parameters.

Solarus now compiles with -Wunused-parameters and -Wunused-variables.
Merge branch 'pedantic' into cpp11