* scd/app-common.h (APP_WRITEKEY_FLAG_FORCE): New.
(APP_READKEY_FLAG_INFO): New.
(APP_LEARN_FLAG_KEYPAIRINFO): New.
(APP_LEARN_FLAG_MULTI): New.
(struct app_ctx_s): New forward declaration.
(struct app_ctx_s): Add members prep_reselect, reselect, and
with_keygrip.
(KEYGRIP_ACTION_SEND_DATA): New.
(KEYGRIP_ACTION_WRITE_STATUS): New.
(KEYGRIP_ACTION_LOOKUP): New.
(APP_CARD): New macro.
* scd/scdaemon.h: Include app-common.h and remove from all other
files.
(app_t): Move typedef to ...
* scd/app-common.h: here.