slapgrid: syntax.

To be able to wrap on all text editors.
slapgrid tests: Remove trailing spaces.
slapos.util: chownDirectory: Add support for different executable locations.
[slapos.core] Add retention_delay support.
[slapos_cloud] Ignore retention_delay from SLA when trying to allocate.
Master: add retention_delay support.
Revert "Master: add retention_delay support."

This reverts commit 0387648c99d46924fd1ef7657eda45dea43c81c4.
Slaptool: Send filter_dict when returning a Partition.
Slaptool: Send filter_dict when returning a Partition (test).
slapos.grid: Adapt retention_delay implementation to support retention_delay being specified in SLA.
Fill changelog.
slapos.core: version up (1.2.4)