configure

configure
+ Darwin sdl linking and cflags on all use of mlt (annoying, but looks unavoidable)

src/framework/mlt.h
+ Include sdl header on Darwin

src/inigo/inigo.c
+ Correction for Darwin key reading from terminal

src/modules/sdl/consumer_sdl.c
src/modules/sdl/consumer_sdl_preview.c
src/modules/sdl/consumer_sdl_still.c
+ Moved initialisation of sdl components to the start/stop methods (Darwin requirement)

git-svn-id: https://mlt.svn.sourceforge.net/svnroot/mlt/trunk/mlt@814 d19143bc-622f-0410-bfdd-b5b2a6649095