Modify bundle header cache handling to properly use synchronized block in all
cases when accessing header cache and to use a separate "uninstalled" header
field to hold the default locale headers for uninstalled bundles. (FELIX-3273)


git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1442600 13f79535-47bb-0310-9956-ffa450edef68