[api] extend distribution list RNG with architecture element.

This will allow OBS 2.5 to have architectures defined per repository and not globally anymore.
[api] support architecture list in default build target /distributions list
[travis] install libsolv perl bindinds
[webui] Fix the case where users have more than one globalrole
[api] do not allow to accept requests which are not in new state (or review with force parameter). Regression fix
[webui] I begin to suspect that testing html5 as XHTML 1.1 is erm suboptimal...
[backend] fix cycle handling in scheduler
[backend] fix project deleting not cleaning up build area in async mode
[backend] fix /published route when there is a partition
[api] do not require SUSE's rpm in the testsuite

Weak dependencies are great to have, but the build service works without them