test: rename test/interactive to interactive-evdev

And share the key-printing functions. In preparation for adding more
interactive-* variants.

Signed-off-by: Ran Benita <ran234@gmail.com>
keymap: move XkbEscapeMapName() to keymap.c.

So we can use it outside src/xkbcomp; it is not really specific to it.

Signed-off-by: Ran Benita <ran234@gmail.com>
keymap: split private functions to keymap-priv.c

This makes it easier to share the private functions in other DSOs
without relying (too much) on dead code elimination, exported symbols,
etc.

Signed-off-by: Ran Benita <ran234@gmail.com>
context: split private functions to context-priv.c

(Same as keymap-priv.c).

Signed-off-by: Ran Benita <ran234@gmail.com>
build: error out on undefined symbols

This helps ensure we don't ship a library with undefined symbols, which
can easily happen with multiple inter-dependent DSOs.

Signed-off-by: Ran Benita <ran234@gmail.com>