BUILD: Can enable/disable asserts at runtime

Makefile.in

configure

configure.ac

inc/lektor/common.h

inc/lektor/lktconfig.h.in

src/base/common.c

src/main/lkt.c

src/main/server.c

src/module/module_repo.c

src/module/module_sdl2.c

src/module/worker.c

src/net/listen.c