Refine function names and type signatures (#886)

* First name consistency pass. More to come!

* Remove multitouch variable (hopefully this compiles!)

* Remove CreationError::NotSupported

* Add new error handling types

* Remove `get_` prefix from getters.

This is as per the Rust naming conventions recommended in
https://rust-lang-nursery.github.io/api-guidelines/naming.html#getter-names-follow-rust-convention-c-getter

* Make changes to Window position and size function signatures

* Remove CreationError in favor of OsError

* Begin updating iOS backend

* Change MonitorHandle::outer_position to just position

* Fix build on Windows and Linux

* Add Display and Error implementations to Error types

* Attempt to fix iOS build.

I can't actually check that this works since I can't cross-compile to
iOS on a Windows machine (thanks apple :/) but this should be one of
several commits to get it working.

* Attempt to fix iOS errors, and muck up Travis to make debugging easier

* More iOS fixins

* Add Debug and Display impls to OsError

* Fix Display impl

* Fix unused code warnings and travis

* Rename set_ime_spot to set_ime_position

* Add CHANGELOG entry

* Rename set_cursor to set_cursor_icon and MouseCursor to CursorIcon

* Organize Window functions into multiple, categorized impls

* Improve clarity of function ordering and docs in EventLoop

src/platform/windows.rs

@@ -33,7 +33,7 @@ pub trait WindowExtWindows {
     /// Returns the native handle that is used by this window.
     ///
     /// The pointer will become invalid when the native window was destroyed.
-    fn get_hwnd(&self) -> *mut libc::c_void;
+    fn hwnd(&self) -> *mut libc::c_void;
 
     /// This sets `ICON_BIG`. A good ceiling here is 256x256.
     fn set_taskbar_icon(&self, taskbar_icon: Option<Icon>);
@@ -41,7 +41,7 @@ pub trait WindowExtWindows {
 
 impl WindowExtWindows for Window {
     #[inline]
-    fn get_hwnd(&self) -> *mut libc::c_void {
+    fn hwnd(&self) -> *mut libc::c_void {
         self.window.hwnd() as *mut _
     }
 
@@ -95,12 +95,12 @@ pub trait MonitorHandleExtWindows {
 impl MonitorHandleExtWindows for MonitorHandle {
     #[inline]
     fn native_id(&self) -> String {
-        self.inner.get_native_identifier()
+        self.inner.native_identifier()
     }
 
     #[inline]
     fn hmonitor(&self) -> *mut c_void {
-        self.inner.get_hmonitor() as *mut _
+        self.inner.hmonitor() as *mut _
     }
 }
 
@@ -109,12 +109,12 @@ pub trait DeviceIdExtWindows {
     /// Returns an identifier that persistently refers to this specific device.
     ///
     /// Will return `None` if the device is no longer available.
-    fn get_persistent_identifier(&self) -> Option<String>;
+    fn persistent_identifier(&self) -> Option<String>;
 }
 
 impl DeviceIdExtWindows for DeviceId {
     #[inline]
-    fn get_persistent_identifier(&self) -> Option<String> {
-        self.0.get_persistent_identifier()
+    fn persistent_identifier(&self) -> Option<String> {
+        self.0.persistent_identifier()
     }
 }