Format Code commad adds '\' before a class name

[felixfbecker]

From @Shababsoft on September 27, 2016 17:2

Format Code command automatically adds the "" before a class when it is used to invoke a static method.
Example:
\testClass::staticMethod()

Copied from original issue: felixfbecker/vscode-php-intellisense#13

[felixfbecker]

This will probably be solved by #35