Some documentation fixes, added test for ImVec2 -> ImRange conversion

src/context.rs

@@ -20,6 +20,7 @@ pub struct Context {
 // This mutex is used to guard any accesses to the context
 static CTX_MUTEX: ReentrantMutex<()> = parking_lot::const_reentrant_mutex(());
 
+/// Check if there is no current context defined by calling into the C++ API
 fn no_current_context() -> bool {
     let ctx = unsafe { sys::ImPlot_GetCurrentContext() };
     ctx.is_null()

src/plot.rs

@@ -181,7 +181,7 @@ impl Plot {
     }
 
     /// Sets the plot size, given as [size_x, size_y]. Units are the same as
-    /// what imgui uses. TODO(4b4) ... which is? I'm not sure it's pixels
+    /// what imgui uses. TODO(4bb4) ... which is? I'm not sure it's pixels
     #[inline]
     pub fn size(mut self, size: [f32; 2]) -> Self {
         self.size = size;