Corrected the url of the file linked to.

Closes-bug: 1278629
Change-Id: I95b682b0fef40df722e2c2a2a9c8a391b77e0b56
Add links to dev docs for some oslo libs

Add links to the developer documentation for oslo.messaging, cliff,
and stevedore.

Change-Id: I0c8edbc5003c0971ffc9728b87d24987a71b2da4
Rename buildlang to buildlang-install

Allow usage of several buildlang jobs in the future.

Change-Id: Ied3bbc2d93273be882d38eb307af6744f023d1f2
Merge "Corrected the url of the file linked to."
Merge "Rename buildlang to buildlang-install"