Implemented modifyAccount method in ProtocolProviderFactory such that we
do not have to uninstall and (re)install the account that has been
edited.
Removed (obsolete) FIXME since now the ChatConversationPanel refactorings have been merged.
Disable port field and check default port checkbox in case a loaded
account is using a default port.
More precise keyword replacement: does not highlight 'fo' in "for".