Squashed 'core/' changes from 9e24e5c..3fc105e

3fc105e Allow optional 'File' field to be 'null'
a65eb6e Fix exception in toString method
831eea7 Merge branch 'feature/issue192' into develop
9048b46 Last changes before the merge
2adea12 Commenting, remove unused code
6fc0daa Minor: Rename config.xml elements to camelCase
e9d29f7 Use custom action aware encryption converters

git-subtree-dir: core
git-subtree-split: 3fc105eb0b468f5db8791fbd478f1640e8112dd8
Merge commit '0d502bc606366b1ced1f184757ff5853aa74c759' into develop