Kept existing funcitonality:
- running the server _manually_ will log to stdout
- running the server as a forked process will log to
~/.megaCmd/megacmdserver.log in POSIX
- log parameters and environment variables will remain working as they
where. Except: Windows no also accepts MEGACMD_LOGLEVEL environment
variable
Changes:
- integration tests will log into $HOME/.megaCmd/megacmdserver.log.
- forked stoud/stderr are now logged to separated files
- refactored some of the from ::executeServer into server main
- removed static `LoggedStream LCOUT(&COUT)` Use Instance pattern
instead. Owned by the executeServer scope.
- adjusted broken identification of source for log lines. Needs
robustifying
- added new LoggedStreamXXX clases (for stdout, for default log file,
for null)
- fix executeInClient args array
