This partially reverts commit c95f5ea, restoring use of Java 8 language
features and APIs to ethereumj-studio, while leaving etherumj-core
pinned to the Java 7 language level for Dalvik compatibility reasons.
For further details, see the prior commit and
https://github.com/ethereum/ethereumj/commit/c95f5ea#commitcomment-9119435.
See updated ethereumj-studio/README.md for details. Note that this
commit removes the `build-post-package.xml` ant file (for now) to
simplify the Gradle arrangement. This functionality can be re-introduced
later and more simply using Gradle's native DSL. In the meantime, both
the -core and -studio projects can be run using `gradle run` or run as
executable jars by running `gradle shadowJar` followed by the usual
`java -jar` execution of the resulting `-all` jar file found in each
project's respective `build/libs` directory.
- Convert ethereumj-studio build from Maven to Gradle as well
- Extract common build elements to top-level build.gradle
- Update top-level README accordingly
Chris Beams