Fixed debug build, simplified sonatype for release only and updated gradle to 1.9 (gradle build tools 7.+
Fixed Lint about formatting strings
Fixed lint about toUpperCase, and backported Arrays.copyOfRange(byte[],int,int) for API < 9
Updated Gradle in Travis CI build config
Provided setter for encoding in RequestParams, closes #406
Merge commit 'cd1855f2c4e204a7cffd65ea755a5eaa700ee3c6'