Fixed counting (errors, warnings) in PHP Code Sniffer plugin

- fix counting of warnings and errors in PHPCI\Plugin\PhpCodeSniffer
- use --report=emacs for phpcs command in PHPCI\Plugin\PhpCodeSniffer

The PhpCodeSniffer plugin did count warnings & errors incorrectly.
It did count the words "ERROR" (or "WARNING"), while those were repeated 2-3 times for each error/warning within the default report, i.e. *phpcs --report=full*.

The PhpCodeSniffer now uses the *phpcs --report=emacs* command line flag, which is also more compact and does not bloat the log so much.

Before: 
```
$ /home/elkangaroo/dev/workspace/php/PHPCI/vendor/bin/phpcs  --standard=PSR1  --extensions=php .

FILE: ...me/elkangaroo/dev/workspace/php/whatsthatgame.git/lib/SplAutoloader.php
--------------------------------------------------------------------------------
FOUND 1 ERROR(S) AFFECTING 1 LINE(S)
--------------------------------------------------------------------------------
 7 | ERROR | Each class must be in a namespace of at least one level (a
   |       | top-level vendor name)
--------------------------------------------------------------------------------
```

After:
```
$ /home/elkangaroo/dev/workspace/php/PHPCI/vendor/bin/phpcs  --standard=PSR1  --extensions=php  --report=emacs .

/home/elkangaroo/dev/workspace/php/whatsthatgame.git/lib/SplAutoloader.php:7:1: error - Each class must be in a namespace of at least one level (a top-level vendor name)
```