Initing eof to false

The call _stream_eof() must return a boolean, not null.
Returning null makes PHP believe that the method wasn't implemented.

Fixes #170
Making Net_SFTP::chdir capable of handling the empty string.

Fixing a ugly notice when using the empty string as parameter for chdir:
  Notice: Uninitialized string offset: -1 in Net/SFTP.php line 617
Making Net_SFTP::chdir capable of handling the empty string.

Updated patch after hint from bantu.
Merge pull request #172 from PVince81/sftp-stream-feof-fix

Initing eof to false
SFTP/Stream: log when constructor is called
Merge pull request #173 from h4cc/patch-1

Making Net_SFTP::chdir capable of handling the empty string.
SFTP: don't do $dir[-1] check if $dir === ''
SFTP: Removed dead code

variable: $initialize = true, ironically - is initialized but never used.
Feel free to deny if this is reserved for future implementation(s).
Merge pull request #176 from phonzie/patch-4

SFTP: Removed dead code

* phonzie/patch-4:
  SFTP: Removed dead code
SSH2: Continue Subsystem Implementation.

Removed unused piece of code @2352.
Added $this->_get_interactive_channel() to reset(). Unless we don't want to close the subsystem channel?? Leaving that decision up to you.
Merge pull request #178 from phonzie/patch-5

SSH2: Continue Subsystem Implementation.
Removed vim comments

Reformated files
Add people from AUTHORS to composer.json.
Use branch name as a subfolder for code coverage reports.
Use a variable for subfolder string.
Add CodeSniffer as composer development dependency.
Add composer.lock file.
The composer.lock file belongs to the repository. Do not ignore.
Remove all ignores that belong to users global .gitignore file.
Only apply git ignores relative to repository root.