PROV-1070 Misc changes

* Make sure locale cache is flushed properly when changes occur (they
rarely do)
* Use proper cache key for element settings of soon-to-be-inserted
metadata elements
* Catch delete key from nonexistent cache
* Flush all caches at start of installer
PROV-1070 Rewrite BrowseCache using new facilities

Also fix whitespaces in BrowseCache. To see the actual changes, append
?w =1 to GitHub URL
NOJIRA Fix indentation in SearchCache