Adding yum_group package_method
Merge pull request #477 from lpefferkorn/yum_group

cfengine_stdlib: Adding yum_group package_method
Merge pull request #482 from sigurdteigen/master

Restructure ExecConfig policy reload, add unit tests
exec-config.c needs cf.nova.h for MinGW build
Update for process.h -> process_lib.h renaming
Use PromiseResult instead of char for promise outcome status in more functions
Honor action_policy => warn in reports promises
Honor classes body in promises with action_policy => warn

This effectively sets not_kept classes if the promise is in need of repair,
but only a warning was issued. This is in line with not_kept counters being
incremented on cfPS(WARN).

Close #2359