Solve Issue #12

Comma added to each line in _osgi.exports_ label of _pom.xml_ to get the correct MANIFEST.MF.

Old MANIFEST.MF only includes the first exported package:
```
...
Export-Package: com.fasterxml.jackson.jaxrs.annotation;version="2.2.3.
 SNAPSHOT"
...
```

And the new generated one includes all the exported packages:
```
...
Export-Package: com.fasterxml.jackson.jaxrs.annotation;version="2.2.3.
 SNAPSHOT",com.fasterxml.jackson.jaxrs.base;version="2.2.3.SNAPSHOT",c
 om.fasterxml.jackson.jaxrs.cfg;version="2.2.3.SNAPSHOT",com.fasterxml
 .jackson.jaxrs.util;version="2.2.3.SNAPSHOT"
...
```