Show the name of the curve and the creation date in the subkey list.
* src/gpa-key-details.c (details_page_fill_key): Add curve info. * src/gpasubkeylist.c (SUBKEY_CREATED): Add new column. (gpa_subkey_list_new): Abbreviate some column titles. Print creation date. (gpa_subkey_list_set_key): Set creation date and curve name.