extabit (download, probe): fix detection of deleted files
core.sh (captcha_process): 9kweu increase timeout of 2x30s

+ add source=plowshare field in request

Credits go to codeworld for original patch.
core.sh (strip): broken! fix regression

Introduced in commit:
core.sh (strip): don't use sed but internal bash built-in
revision b349ccbebf8644c7a37c78988f03ba58f595b4fd

Behavior is different with "<<<" input
Also note thar
$ read -r && echo "[$REPLY]"
and
$ read -r A && echo "[$A]"
are giving different results!
rapidgator (upload): update, anonymous upload no longer allowed
letitbit (probe): fix - provide at least basic information

Full information (including file size with byte precision and hash
value) is only available from the form that is now obfuscated.
mediafire (download): fix - better captcha and redirect detection

Also fixes broken debug output in 'mediafire_extract_id', a regression
introduced in 4d320eb77d8058970fac9f9d0180445f728b0b40
mediafire (download): fix SIGPIPE/141 error