Modified POM for bundle packaging

Changed packaging to bundle, changed version to match forked Bukkit, added maven-bundle-plugin invocation
Removed maven-shade-plugin invocation
Changed Ebean dependency to be imported as a bundle
Added split-package directive to net.minecraft bundle export
Converted commons-lang dependency to bundle dependency
Converted guava dependency to bundle dependency
Converted snakeyaml dependency to bundle dependency
Converted gson dependency to bundle dependency

Gson bundle can be installed in karat with:

osgi:install mvn:com.google.code.gson/gson/2.2.2
Embedded mysql-connector-java and sqlite-jdbc jars
Converted jline, jansi, and joptsimple dependencies to bundle dependencies

joptsimple is available from servicemix maven repo:

osgi:install mvn:org.apache.servicemix.bundles/org.apache.servicemix.bundles.jopt-simple/4.3_1
Revert "Removed maven-shade-plugin invocation"

re-shaded minecraft-server without relocations, made org.bouncycastle package-private

fixes #3
Made org.ibex.classgen import optional

fixes #4
Made org.jboss.resource.adapter.jdbc an optional import

fixes #5