Bump version to 0.1.9

We have significant changes in this new release thanks to the solid contributions from the community:
- New generic functions - check the documentation for more details
- Major refactoring and code cleanups
- Better image format handling

setup.py

@@ -14,7 +14,7 @@
 
 setup(
     name=PACKAGE_NAME,
-    version='0.1.8',
+    version='0.1.9',
     author='Samuel Hoffstaetter',
     author_email='samuel@hoffstaetter.com',
     maintainer='Matthias Lee',