Add optional arg to delete-file to force deletion (Bug#6070).

Add optional arg to delete-file to force deletion (Bug#6070).

* eval.c (internal_condition_case_n): Rename from
internal_condition_case_2.
(internal_condition_case_2): New function.

* xdisp.c (safe_call): Use internal_condition_case_n.

* fileio.c (Fdelete_file, internal_delete_file): New arg FORCE.
(internal_delete_file, Frename_file): Callers changed.

* buffer.c (Fkill_buffer):
* callproc.c (delete_temp_file): Callers changed (Bug#6070).

* lisp.h: Update prototypes.

* diff.el (diff-sentinel):

* epg.el (epg--make-temp-file, epg-decrypt-string)
(epg-verify-string, epg-sign-string, epg-encrypt-string):

* jka-compr.el (jka-compr-partial-uncompress)
(jka-compr-call-process, jka-compr-write-region, jka-compr-load):

* server.el (server-sentinel): Use delete-file's new FORCE arg
(Bug#6070).