Hotfix #1 for 0.7

In a few days, Hotfix #1 for apugg 0.7 will be released. It will be version 0.7.1, and will fix the following bugs only:
* [#27] Memory leak in Kernel
* [#28] New get pugg version method
* [#24] Add 0.7 to history

This hotfix will be pushed to the branch 'hotfix_0.7_1', and from there merged into develop and release_v0.7. The merge commit on the release branch will be merged into master and there tagged as 'v0.7.1'.

We hope to get this out in 2-3 days at the most.

Thanks!