Rewrite entire plugin to use java card ant skripts

- replace cap taks by ant based convert task
- move javaCard.sdk to environment variable
- drop cap section from config file and therefore also CapExtension
Factor out ConvertJavacard task

- introduce reusable task class
- enable conventions mapping from JavacardExtension to task
Unify the camel-case style to javacard

* remove all javaCard strings and replace accordingly
Add test for the JavacardPlugin and -Extension
Fix error when extracting package name
Add test for ConvertJavacardTask
Introduce JC_HOME validation
Improve plugin unit tests
Add gradle wrapper
Merge pull request #3 from fidesmo/proting-to-ant

Use java card ant classes instead of calling executables directly