Bugfixes: connecting to server error, sleeping in unsent service

* src/smime-gate.c
Bugfix #1: when unable to connect to server S/MIME Gate Service process
           was just terminated -- unsent mails were not moved to "unsent
           directory".
Bugfix #2: Unsent Service should rather try to send all unsent messages
           on the startup (than sleeping first).
Benchmark environment, debug messages, cleanup

* src/main.c
* src/smime-gate.c
Added debug messages.

* testing/Makefile
* testing/Makefile.dep
+ testing/smtp-benchmark/server.c
+ testing/smtp-benchmark/smime-gate
+ testing/smtp-benchmark/smime-tool
Created new environment for testing (benchmark).

+ .gitignore
Created .gitignore file.