several fixes and performance improvements

Several fixes, performance improvements, and added logging:

- editors now report when they're modified (as well as when they're dirtied). This lets us listen for modifications, and only auto-save an editor once it's been ~1 seconds since it was last modified. Before, we saved every second, even if the user was still typing
- added logging info for builds, jobs, and scm status
- fixed some checked mode issues in git, including a `modificationTime` assignment issue
- made project refresh twice as fast, by waiting on the futures in parallel, instead of sequentially
- changed our exception catcher to not catch when running in developer mode
- we don't emit info level log messages if not running in dev mode
- fixed an issue where modifying a workspace resource would fire two change events
- changed scm status to not request status for files in the `.git` folder (like the index file)

Sorry for the un-focused nature of this CL - was fixing issues as I ran into them.

@sunglim and @gaurave for review