Bumped release version.

1. Regenerated smart contract wrappers.

2. Added suppress warning annotation to codegen for working with array types.
3. Bumped version to 3.3.1.

Merge remote-tracking branch 'origin/master' into android

# Conflicts:
#	build.gradle

Merge pull request hyperledger-web3j#346 from TiesNetwork/master

Contract wrapper generator should convert array items to native types

Updated version.

Updated version to 3.1.1 in docs.

Merge pull request hyperledger-web3j#243 from joanesespanol/android

Android

1. Added MetaCoin smart contract wrapper to integration-tests module …

…and build script.

2. Documentation updates.

1. Bumped version.

2. Added toBigIntNoPrefix utility function.

Updated version in conf.py.