Add missing FeatureNew for libwmf dependency

Also add it to the release notes for the 0.44 release.

https://github.com/mesonbuild/meson/pull/3709#issuecomment-395738573

docs/markdown/Release-notes-for-0.44.0.md

@@ -145,3 +145,9 @@ myprog = find_program('myscript.py')
 ```
 
 Then Meson will run the script with its internal Python version if necessary.
+
+## Libwmf dependency now supports libwmf-config
+
+Earlier, `dependency('libwmf')` could only detect the library with pkg-config
+files. Now, if pkg-config files are not found, Meson will look for
+`libwmf-config` and if it's found, will use that to find the library.

mesonbuild/dependencies/misc.py

@@ -517,6 +517,7 @@ class CupsDependency(ExternalDependency):
 
 
 class LibWmfDependency(ExternalDependency):
+    @FeatureNew('LibWMF Dependency', '0.44.0')
     def __init__(self, environment, kwargs):
         super().__init__('libwmf', environment, None, kwargs)