Support for external js/css sources file. Closure language-in option.
Merge branch 'master' of git://github.com/ssaarela/minify-maven-plugin into closure-language

Conflicts:
	src/main/java/com/samaxes/maven/minify/plugin/MinifyMojo.java
	src/main/java/com/samaxes/maven/minify/plugin/ProcessJSFilesTask.java
Add support for Google Closure Compiler 'language' option