keyserver_work), hkp.c (hkp_ask_import, hkp_export, hkp_search): Use a
much more strict reading of RFC-2396 for the keyserver URIs. Specifically,
don't try and be smart about checking the value of ":port" so long as it
is all digits, and properly handle opaque data (those scheme specific
parts that do not start with "//").
FIXED_PHOTO_VIEWER and DISABLE_PHOTO_VIEWER.
* mainproc.c (check_sig_and_print): Use --show-photos to show photos when
verifying a sig made by a key with a photo.
* keyserver.c (parse_keyserver_uri): Properly parse a URI with no :port
section and an empty file path, but with a terminating '/'.
(keyserver_work): Honor DISABLE_KEYSERVER_HELPERS.
* hkp.c (hkp_ask_import): Display keyserver URI as a URI, but only if
verbose.
* exec.c, g10.c: USE_EXEC_PATH -> FIXED_EXEC_PATH
