* dialog-hyperlink.c (struct HyperlinkState): Add sheet control,
internal link expr entry and is_new flag.
(dialog_hyperlink_free, cb_cancel, cb_ok)
(dialog_hyperlink_setup_type, dialog_hyperlink_set_type)
(cb_menu_activate, dialog_hyperlink_init): Rename to dhl_xxx.
(dhl_set_tip): New. Set "tip" field in dialog.
(dhl_get_tip): New. Get "tip" field from dialog.
(dhl_set_target_cur_wb): New. Set "target range" field in internal
link variant of dialog.
(dhl_get_target_cur_wb): New. Get "target range" field from
dialog.
(dhl_set_target_external): New. Set "file" field in external link
variant of dialog.
(dhl_get_target_external): New. Get "file" field from dialog.
(dhl_set_target_url): New. Set "Web address" field in URL variant
of dialog.
(dhl_get_target_url): New. Get "Web address" field from URL
variant of dialog.
(type): Add set_target and get_target methods.
(dhl_set_target): New. Set target field in dialog.
(dhl_get_target): New. Get target field from dialog.
(dhl_cb_ok): Use the results.
(dhl_set_type): Unref old.
(dhl_init): Don't call gnumeric_editable_enters on
entries. Instead, we set "activates_default" to true in the glade.
Conditionalize email link and disable for now. Reason: needs RFC
2047 header encoding/decoding.
(dialog_hyperlink): Init state->sc, state->internal_link_ee and
state->is_new. Ref the link. Drop last_link_type. Use
dhl_setup_type instead of dhl_set_type.

* hyperlink.glade: Set dialog invisible. Set activates_default to
true for entries.