initial implementation

To-be-reviewed-by: mm0zct
fix typo

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
while here, clean up -Wall -Wextra -pedantic

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
fix wrong colors

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
while here, remove dead code

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
remove dead code

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
don't even display headpose when off

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
fix the damn mess

Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
New feature: tracker disablement on keystroke

Requested-by: Patrick Ruoff (c14)
Reviewed-by: mm0zct (first commit)

Untested on Win32! Not even compile-time-tested...

Merge remote-tracking branch 'origin/feature/toggle-tracking-enabled-20131016'