Improve Concurrency of Build Update Operations

There is currently the opportunity for race conditions to occur when updating build results. Builds read from session can sit a while before being saved and when saved will overwrite any changes that occurred in the mean time.

See http://jira.atlassian.com/browse/BAM-3949 for a nice example of the problems it can cause...

The idea behind this task is to move all core operations that occur on a build to the build manager/dao to be performed in a similar way to the way we increment the next build number (i.e safer).
Key candidates for moving include:

• Setting first and last build number
• The suspended from building (maybe)
• I would also check the vcs revision key, for concurrency issues, though it already gets updated within the build manager.

We have implemented dynamic updates to reduce the probability that these problems can occur and the build does not actually get updated that often so the risks are quite low, however it still should get looked at.