[backend] Add armv6hl

Adds support for armv6hl, which is an ARMv6 little endian hard float
target.
[webui] port the saving of the failed comment attribute
[api] go through daemons in workerstatus
[webui] url encode the project and package for download link
[api] Fix forbidden_projects_ids query

The project access flag has two status: "enable" and "disable" - the latter
must be queried for forbidden_project_ids.
[api] move write permission checks from controller to package and project model

This is just the first part doing the checks. Removing the old ones is another step.
[webui] title is not a valid parameter to the live_build_log action
[api] do not allow request from source on same target, when a source modification option is used
[webui] Fix request/release dialogs
[api] don't hardcode ruby1.9
[backend] make kiwi parsing in bs_worker more robust, use Build::parse
[doc] update informations about the official books of OBS
[webui] fix old links to project/monitor pages