mark functions and vars as static (#146)

the goal here to mark functions and variables not used outside the
translation unit as static. main reason for this is cleanliness. however
as a side-effect this can help compilers optimize better as it now has
guarantee that a certain function won't be called outside of that
translation unit.

one other side-effect of this is that accessing these vars/function from
config.h is now different.

if one wants to access a static var/func from different translation unit
in config.h, he would have to create a wrapper function under the right
ifdef. for static functions one would also need to forward declare it.
here's a dummy example of accessing the function `run_key_handler` from
config.h under _MAPPINGS_CONFIG

```
static void run_key_handler(const char *, unsigned);
bool send_with_ctrl(arg_t key) {
	run_key_handler(XKeysymToString(key), ControlMask);
	return false;
}
```

1 files changed, 0 insertions, 2 deletions

diff --git a/nsxiv.h b/nsxiv.h
index 6c1f5f9..618a1ac 100644
--- a/nsxiv.h
+++ b/nsxiv.h
@@ -233,7 +233,6 @@ bool img_fit_win(img_t*, scalemode_t);
 bool img_zoom(img_t*, int);
 bool img_zoom_to(img_t*, float);
 bool img_pos(img_t*, float, float);
-bool img_move(img_t*, float, float);
 bool img_pan(img_t*, direction_t, int);
 bool img_pan_edge(img_t*, direction_t);
 void img_rotate(img_t*, degree_t);
@@ -283,7 +282,6 @@ struct opt {
 extern const opt_t *options;
 
 void print_usage(void);
-void print_version(void);
 void parse_options(int, char**);