Fix whitespace error and reversed boolean bug in pwsafe-v3.tcl
introduced in previous commit.
Partial history GUI implimentation
Empty history list GUI before inserting new records.

Remove a static text insert code line that was used for initial
development.
Disable/Enable show and generate password buttons based upon history
pane visibility.
Toggle to normal password edit view if reused edit window was set to
history view when last closed.
More complete GUI for managing password history.

Most of the interface for manipulating per record on/off state and
maximum length value built now.
Reorder save code to process history flags first, so that changes in
active state are processed before password changes.
Tweak GUI layout for history pane - move active toggle checkbutton out
of main history pane into global button area.

Implement revert button functionality.
Fix two incomplete history structure initialization bugs that occurred
when creating a brand new record.
Implement preferences pane for the PWSafe V3 history feature.

This commit adds an additional tab to the preferences tabs dialog for
controlling the initial values given to new password records, and to
existing records that have no history field in the PasswordSafe file.