Fixed  #109 (Update Change number of drops in Identity class) and #128 (Fixed Identity constructor should set QblPrimaryKeyPair)

Update Change number of drops in Identity class #109 
Fixed  Identity constructor should set QblPrimaryKeyPair #128

Please also check the issue #147 because a test crashed
`Collections.unmodifiableCollection(this.accounts)` - I like that!
https://github.com/Qabel/qabel-core/pull/145/files#diff-d8142b906e2c1cddb5b15854066b00a3R20